Byron's Gasser Madness!

~ Gasser Classes  ~

In 2004 I wrote a series of short articles for Gasser Wars Magazine offering a retrospective of the rules governing Gasser class cars over the years.  What follows is a slightly updated version of those articles...still missing the last chapter which I suppose I'll get around to writing one of these days. (Click on the thumbnails for larger photos.)

Note: Feb 2010; John Shelton of American Gasser has created a nice summary chart of the year-by-year changes.

You can click HERE to see it.

It’s a matter of class!

By Byron Stack

2004, 2005, 2010

 One of the most commonly asked questions emailed to my website is something regarding the gasser classes.  It seems that many of the younger fans just don’t understand the classifications…and a lot of us older ones have forgotten a lot.  The letters I have trouble answering are those where the writer clearly doesn’t understand the concept of weight vs. engine size as the determining factor.  Don’t get me wrong, I don’t blame them, it’s just that they’ve never seen anything but indexed or unlimited classes.  The concept of classifying a car without some sort of performance factor is completely alien to them.

Of course that’s about how I felt when attending a dragrace for the first time in 1997 after a 25-year absence…”What’s an index?”

When I decided to write this article, I wasn’t really sure how to go about it.  First of all, I needed real facts.  Heck, I didn’t remember what the class breaks were in 1965.  I didn’t remember which years the classifications changed from A/G to A/GS to AA/G to AA/GS.  Therefore I want to start by thanking Steve Gibbs at the NHRA Motorsports Museum for supplying me with Xeroxed copies of NHRA rule books from 1958 through 1972…although there were a couple of years missing, they gave me the kind of information I needed.

The second problem was just how to organize the information.  I didn’t want to just publish a table with all the numbers on it, I wanted to be able to relate it to something tangible and to provide some sort of continuity.  When Phil Morris suggested that I break the article into sections for publication over a few issues, I had what I needed.  I finally had the barest clue about how to write this thing.  Just a clue, mind you, but a clue, nonetheless.

Keep in mind that all the information here is based on NHRA rules.  While AHRA rules were similar, there were some differences (different weight breaks, etc).  Additionally, many tracks used their own sets of rules based on what was available to race in the local area.

 The Fifties

 First, let’s talk about gassers in the fifties.  Now, to be honest, these cars were a bit before my time.  I was around throughout the fifties, but didn’t “discover” dragracing until the early sixties, so what I do know about fifties gassers is pretty much culled from a 1958 NHRA rulebook (courtesy of Steve Gibbs), a conversation or two with Don Montgomery (author of “Supercharged Gas Coupes & Sedans”), conversations with other racers of the era, and photos and articles of the time. 

Having said that, let’s see what we can uncover about the early gassers.  In what is generally accepted as the first legal drag race ever, in 1949 at Goleta, CA, Tom Cobb’s blown flathead Model A roadster lost to Fran Hernandez’ nitro-burning flathead, fenderless 32 coupe.  Well, no gassers there…but at least the coupe won!  About a year later, on Sunday June 19, 1950, C.J. “Pappy” Hart opened the first legal dragstrip in the nation on an unused runway at Santa Ana, CA.

At first, there were no “classes”.  It was “run what ya brung” in the purest sense.  Interestingly enough, by the way, more often than not, it was a motorcycle winning the top eliminator.  By 1953, some general classes were introduced.  They were pretty loose and included classes like “Pre-War Roadster” and “Post-War Heavy Sedan” among others.  As time progressed, the classes became more formalized.  That was also the year that the NHRA held it’s first drag race at Pomona.  Two years later, in 1955, they held their first national event in Grand Bend, Kansas.

To be truthful, I don’t really have any information about class structures until 1958, so I’m going to have to start there with any kind of specifics.

In 1958, a gas class racer was basically a hot street coupe.  No engine setback was allowed, all gassers had to have working lights, wipers, starter, generator and all other street equipment.  Fans and belts were optional, but radiators were required.  The car even had to be currently licensed for the street.  Full exhaust systems, including mufflers, were required but could be unhooked for competition, although they had to remain on the car.  Those of you who (like me) are old enough will remember “cutouts” that were used back then up into the early to mid 60’s. 

What all this provided for was a class for guys to run a “hopped-up” street machine.  The cars were required to have full “factory-type” upholstery although two buckets could replace the standard bench seat as long as both were fully upholstered.  Customs were allowed as long as the car wasn’t chopped, channeled or sectioned a total of more than four inches.  “Four stock fenders” and a rear bumper were also required.

Full transmissions were required, as were “Quick-change rear-ends, locked differentials or ratchet-type rear-ends (high torque) are permissible with safety hubs.”  Four-wheel brakes were required as well.

There were only five gas classes, classified according to total car weight divided by total engine displacement cubic inches.  Designations were A/G, B/G, C/G, D/G or E/G preceded by car number.  Use of a supercharger moved you up one class.  The breakdowns were as follows:

Class A 0 to 8.99 pounds per cubic inch
Class B 9.00 to 10.99 pounds per cubic inch
Class C

11.00 to 12.99 pounds per cubic inch

Class D 13.00 to 13.99 pounds per cubic inch
Class E 14.00 or more pounds per cubic inch

As you can see, this class was designed for what was basically a modified stocker…much like the later Modified Production classes.

By 1960, the rules had changed significantly.  By then, engine setback of up to 10% was permitted although most of the street equipment rules were still in force.  Since I don’t have access to a 1959 rulebook, I can only surmise that the setback rule took effect first in either 1959 or 1960.

Just by way of providing information for those who aren’t quite sure what “engine setback” means, a 10% setback would allow the engine to be moved back enough so that the forward most sparkplug in the engine could be no further than 10% of the wheelbase behind the front axle centerline.  In other words, if the car had a 100" wheelbase, the front sparkplug must be within 10" of the front axle centerline.

The reason that the setback rule was introduced is reasonably simple.  There was nothing in the rules that required the original engine in the car to be used.  When someone performed an engine swap in a Model A, for instance, chances were that they would have to cut the firewall anyway.  The question then becomes “what is the “stock location” for a flathead V-8 in a Model A?”.  Introducing an engine setback limitation merely provided a level playing field for all competitors.

Next we’ll talk about the “Golden Age” of the gassers, the 1960’s. 

The Sixties

The sixties was a weird decade.  Books ranged from “To Kill A Mockingbird” in 1960 through “Unsafe At Any Speed” in 1965 to “The Electric Kool-Aid Acid Test” in 1967.  Movies were equally eclectic, from “The Sound of Music” and “My Fair Lady”, to “Dr. Strangelove or how I Stopped Worrying and Learned to Love the Bomb”, “The Graduate”, and “Midnight Cowboy”.  President John F. Kennedy was assassinated in Dallas, TX.  We became mired in Vietnam.  The artificial heart was invented.  We put a man on the moon.  We started off the decade listening to Neil Sedaka, Bobby Darin and Paul Anka on our AM radios and as the decade progressed, we were listening to the Beatles and the Rolling Stones who were eventually joined by Hendrix, Janis, The Grateful Dead and the Jefferson Airplane on FM.  And then there were Woodstock and Altamont, both in 1969.  As I said before, the sixties was a weird decade. 


 The sixties was also the decade that dragracing became the world’s most popular motorsport…and in my opinion, deservedly so.  As the sixties started, the drags were still generally more of a participant than a spectator sport, although that changed rapidly (and, like many other activities, it’s still more fun to take part than it is to watch).  Take a look at the Steve Gibbs photo of Junior Thompson’s Willys at San Gabriel in 1963, and the Doug Peterson photo of Lions in 1960 and you’ll have a pretty good idea of what I’m talking about when I say it wasn’t very spectator oriented.

 1960 was the very first year for the new Supercharged Gas classes.  I don’t have copies of the rulebooks for 1960 or 1961, but the basic rules were unchanged from the late 50’s.  The cars were still required to have full street equipment, including registration and plates.  A maximum engine height of 24” from the ground to the crankshaft centerline was established.  Minimum wheelbase was increased from 86” to 92”. Weight breaks were little changed from what I showed previously with the following exception.  For the 1961 season A/Gas and A/GS classes were changed to provide for a minimum weight of 4.00-lbs./cu. in. from the previous 0.00 minimums.

 1962 was a sort of “sea change” year for the gassers.  As Don Montgomery, in his book “Supercharged Gas Coupes & Sedans” states: “The NHRA rule changes for 1962 were evidence that drag racing had finally accepted the gas coupe/sedan competitors to be serious racers.”   The rules that required full street equipment including mufflers, wipers, horns, generators, emergency brakes, license plates and registration were now gone.  Roll-up side windows were no longer required and could be replaced by Plexiglas windows screwed to the window frame.  They were now real racecars.  The other change, affecting only the A/GS class was the decision to raise the minimum weight to 5.00-lbs./cu. in.  Performances of the blown cars were getting pretty quick.  I still remember reading in Hot Rod Magazine about Stone, Woods & Cook breaking the 10-second “barrier” with a 9.99 at Fremont.  The supercharged gassers were the quickest and fastest full-bodied cars in drag racing.

 There were only a couple of rule changes for 1963.  The first raised the minimum weight for A/GS cars to 6.00-lbs./cu. in. and the second allowed, even though they only had a 90.5” wheelbase, 48-53 Anglias to compete in the unblown classes with small block engines.

 1964 was the start of the “Gasser Wars”.  It was also the first year I ever attended a drag race…and it’s where we’ll start the next installment.


1964 was the first year that I ever attended a drag race, specifically, it was the “First Annual Hot Rod Magazine Drags” at Riverside, CA.  I remember when the meet was first announced in HRM.  I immediately sent in my $4.00 for a 3-day pass (yes, really, $4.00 for a 3-day pass!) and shortly received ticket # 000042.  At Riverside I watched a number of legends win their classes, “Big John” Mazmanian in A/GS, Hugh Tucker in AA/SR, one of my favorites, Les Barath in the “Freedom Fighter” Simca won A/MSP, Manuel Herrera won B/G, Gas Ronda took S/S.  One thing I remember well is that I was immediately hooked for life!

In 1964, the basic rules for Gassers were unchanged from 1963.  As mentioned in the previous segment of this series, many of the rules were changed in 1962 and the Gassers were now much less “dual-purpose” street & strip machines than had been required prior to 1962.  The bodies were required to be “a coupe or sedan body originally produced by an American automobile manufacturer”, with the following exception “There are at present a few foreign coupe and sedan bodied cars that, in general characteristics, better meet the requirements of Gas Coupes/Sedans class better than sports car class.  Provided these car bodies and cars do meet all other class requirements – wheelbase, etc. – these cars are classed according to cubic-inch displacement to weight under this section.” 

As in 62 and 63, the Anglia was restricted to small-block, unblown engines only.

Moderate customizing was permitted, but the total height of the body still couldn’t be reduced more than 4”.  Fiberglass fenders, hoods, doors, and trunk lids were allowed, but their use required the addition of a roll bar which was otherwise only required in the supercharged classes, A/G, and all convertibles or customized classes. Yes, convertibles were permitted in the Gasser classes, but had to run with the top up.

The rules also required the seats to be in the stock location, but they were permitted to be relocated no more that 4” rearward to allow additional legroom.  The other interior rules were subject to a lot of interpretation.  The rules for “Upholstery” read as follows: “Interiors may not be gutted.  Must run full upholstery, equivalent to factory specifications.  Floor mats optional.  Bucket seats may replace stock seats (two required), only if they are fully upholstered.  Rear seats are optional.  Factory type upholstery and/or paneling must be used in lieu of the above.”  So…basically, you could rip out the stock seats and carpeting, replace them with lightweight bucket seats and dump the rear seat.  Sounds like “full upholstery, equivalent to factory specifications” to me…yeah, right.

The class breakdowns were according to the following tables.

Supercharged classes:


6.00 to 8.99 lbs. per cubic inch


9.00 to 12.59 lbs. per cubic inch            


12.60 or more lbs. per cubic inch

 Unsupercharged classes:


5.00 to 8.99 lbs. per cubic inch


9.00 to 10.49 lbs. per cubic inch


10.50 to 11.49 lbs. per cubic inch


11.50 to 12.99 lbs. per cubic inch


13.00 to 14.59 lbs. per cubic inch


14.60 or more lbs. per cubic inch


5.00 to 10.99 lbs. per cubic inch


11.00 or more lbs. per cubic inch

G/Gas and H/Gas were for non-supercharged pre-1960 flathead V-8’s, in-line six cylinder and straight eight engines with stock production-type heads and pre-1960 unblown 4-cylinders with any type head.

 For 1965, about the only noticeable change in the rules was the addition of a “Batteries” section which required all wet-cell batteries to be located outside the passenger and driver compartment.  The rules also specified that a maximum of 2 passenger car batteries may be used and they couldn’t weigh more than 150 pounds combined.   No more of those 400 pound truck batteries!

Although the rules for NHRA remained the same as far as the Anglia, etc. were concerned, NHRA was NOT the only game in town.  The AHRA had made terrific inroads and, particularly in Southern California, AHRA had no problems with blower motors in the small cars.  Shores & Hess put the first blown small-block Chevy in an Anglia, followed shortly by the Kohler Brothers.  Upping the ante a few weeks later, the Kohlers dropped in a blown big block and were followed a week or two later by Shores & Hess doing the same.  These cars were tremendously popular in Southern California, and the handwriting was on the wall.   Just as an aside, Skip Hess is generally given credit for coining the term “Rat Motor” for the big-block Chevy when he had Jack Burr add that lettering to the scoop on the Shores & Hess Anglia when the big motor was put in the car.

1966 saw a redistribution of the unblown classes as shown in the following table:



5.00 to 6.99 lbs. per cubic inch


7.00 to 8.99 lbs. per cubic inch


9.00 to 10.99 lbs. per cubic inch


11.00 to 12.99 lbs. per cubic inch


13.00 to 14.59 lbs. per cubic inch



Unchanged from 1965



 The other change for 1966 was some slight changes in the weight breaks for the supercharged cars, and a redefinition of the classes.  Instead of being known as “A/Gas Supercharged”, for instance, it would now be known as “AA/Gas”.  NHRA’s stated reason was to bring the class designations more in line with the rest of the classes where the double letter (AA, BB, CC) itself designated the class as a supercharged class.

 Though I suppose it seems silly in retrospect, I do recall that this change was NOT popular among the racers of these cars.


6.00 to 8.99 lbs. per cubic inch


9.00 to 11.99 lbs. per cubic inch


12.00 or more lbs. per cubic inch

 The rules for 1967 were unchanged for unblown gassers running A/Gas through F/Gas.  The “flathead” classes G/Gas and H/Gas saw some major changes though.

G/Gas, at 5.00 or more lbs. per cubic inch, was now for “Non-supercharged flathead V-8’s, in-line six-cylinder, opposed six-cylinder and straight-eight engines with any type head.

H/Gas, 11.00 or more lbs. per cubic inch, was for the same engines but with stock production-type heads.

Noticeably absent from the “Wheelbase” section of the rules in 1967 was the passage specifying “small-block” only power for the Anglia.  The supercharger was still forbidden, however.

The blown gas classes were realigned somewhat as shown below.


5.00 to 7.99 lbs. per cubic inch


8.00 to 10.99 lbs. per cubic inch


11.00 or more lbs. per cubic inch

 1967 was also the year when the newer body styles began showing up in the Gasser classes.  While many decry this as the “death of the Gassers”, keep in mind that the racers in the classes were there to WIN, not to keep things “nostalgic”.  They merely took advantage of the existing rules as written in order to try to win races.

Next time, we’ll tackle 1968 (and the return of the “S” to the supercharged class designations) and subsequent years.


These were a couple of tumultuous years in the world.  In January of 1968 the USS Pueblo was captured by the North Koreans, and the Tet Offensive started in Vietnam.  By the end of December, Martin Luther King and Robert Kennedy were dead, the Paris Peace Talks had begun, the Democratic Convention in Chicago had seen incredible violence, Arlo Guthrie performed his 20 minute ballad "Alice's Restaurant", Jacqueline Kennedy married Aristotle Onassis, and Richard Nixon was elected President.

1969 saw man land on the moon, the Woodstock Festival, the first Nuclear Non-Proliferation Treaty, Senator Edward Kennedy at Chappaquiddick, MA, the Rolling Stones concert at Altamont (widely heralded as the end of the “Flower Power” days), the first in vitro fertilization of a human egg, DARPANET (the original foundation upon which the Internet would eventually be based) went online to connect 4 major universities, and the use of DDT was banned in residential areas.

The world of drag racing wasn’t nearly as tumultuous.  While there were changes, there was nothing really earthshaking.  In the Supercharged Gas classes, the “S” was back!  I mentioned previously that while it may seem silly now, changing the class designations from A/GS to AA/G, B/GS to BB/G and C/GS to CC/G was not a popular change with the racers.  Well, they won…sort of.  As of 1968, the classes were designated AA/GS, BB/GS, and CC/GS.  I suppose that made everyone happy.

As far as other changes for the gas classes, there were some fairly big changes.  The biggest was probably in the frame section of the rules.  AA/GS through B/G and all cars with unibody construction would now be allowed to use rectangular or square steel tubing in frame construction.  The minimum was .120 wall thickness and 2x3 inch rectangular or the equivalent square tubing.  Prior to this, the rules called for a “stock automobile type frame”.

 The weight breaks for the blown cars were unchanged from the prior year, but a little bit of “Tightening up” took place in the upper ranks of the unblown classes and the major shakeup was in the G/Gas  and lower classes.  The class designations were as follows:



5.00 to 6.49 lbs. per cu. in.

Was 5.00 to 6.99 lbs. per cu. in.


6.50  to 7.99 lbs. per cu. in.

Was 7.00 to 8.99 lbs. per cu. in.


8.00 to 9.49 lbs. per cu. in.

Was 9.00 to 10.99 lbs. per cu. in.


9.50 to 10.99 lbs. per cu. in.

Was 11.00 to 12.99 lbs. per cu. in.


11.00 to 12.49 lbs. per cu. in.

Was 13.00 to 14.59 lbs. per cu. in.


12.50 to 13.99 lbs. per cu. in.

Was 14.60 lbs. per cu. in. or more


14.0 lbs. per cu. in. or more.

Was flathead class


6.00 to 8.99 lbs. per cu. in.



9.00 to 11.99 lbs. per cu. in



12.00 lbs. per cu. in. or more.



10.00 lbs. per cu. in. or more.


 A bit of explanation is probably in order regarding the H/Gas through K/Gas classes.  The H, I, and J classes were for “Non-supercharged flathead V-8s, in-line and opposed six-cylinder, straight-eights, and in-line and opposed four-cylinder engines with any type heads.”  K/Gas was for “Non-supercharged flathead V-8s, in-line fours or sixes and straight-eight engines of American manufacture with stock production type heads installed in American production bodies.”  Basically what was happening was that NHRA was making a place for the VWs and Fiats that were starting to appear in great numbers in the lower gas classes. 

In 1969, while AA/GS remained unchanged, BB/GS tightened up from requiring 8.00 to 10.99 lbs./cu. in. to 8.00 to 9.99 lbs/cu. in. and anything at 10.00 or more lbs/cu. in. was now in CC/GS.

A/Gas through E/Gas were also unchanged, but F/Gas was now 12.50 or more lbs./cu. in.  Another reshuffling took place below that, as G/Gas was back to a flathead class and K/Gas was dropped.  The breakdown is as follows:


6.00 to 7.99 lbs. per cu. in.

Was H/Gas


8.00 to 10.99 lbs. per cu. in.

Was I/Gas


11.00 lbs. per cu. in. or more.

Was J/Gas


10.00 lbs. per cu. in. or more.

Was K/Gas




 Other than that, the big news was that blown Anglias were now legal in NHRA.  Prior to 1969, Anglias, with their 90 inch wheelbase, were only legal for the unblown gasser classes.  As of 1969, NHRA lowered the minimum wheelbase from 92 inches to 90 inches.  Of course, that didn't matter too much, since the older bodied (Anglias, Willys, etc,) cars were rapidly becoming uncompetitive next to the more modern bodied cars.

Next up…the end of the gassers…and this series of articles.