NHRA's ruling on "Single Booster" Quadrajets

[Danny Ashley]

I was informed Friday at Indy by Travis Miller that the 1971 Pontiac quadrajet we in the business refer to as the "Single Booster" will only be permitted on the engines that were originally equipped with them. For those of you who have never heard of them , here's the story. All Q-Jets ,except these, have a main and two booster venturis. In 1971 only, Pontiac had Rochester build a Quadrajet without the larger of the two
booster "rings". # 7041263 was put on the 400 & 455 "standard" engines. #'s 7041267 & 7041268 on the 455 H.O.'s and #'s 7041270 & 7041273 on the 455 Ram Air's. The kicker is that not all 1971 Pontiac Q-Jets are single boosters. # 7041262 was put on the "standard" 455 while # 7041264 on the "standard" 400. The story goes that some customers complained of a low speed lag with the single boosters and the dealerships would replace them with # 7041262 or 7041264. NHRA believes that the single boosters flow more air-fuel mixture and would be an "unfair-advantage" when used on another engine. Racers have been using them for years because the main venturi does measure 1.093 which is the correct measurement for all makes of engines that require this specification for the smaller of the two sizes Rochester made. The other is 1.218" for the 800 CFM. So if you know of any racer that is running a single booster, please tell them the ruling because I doubt that we'll read about it in National Dragster. I don't wan't anyone to be surprised in the barn. I had one of these to do for a Pontiac Stocker racer ( 1972 455 ) when I returned from Indy so I called and and gave him the bad news. What a shame because they are rare and expensive. I'd like to clear up a mis-conception about what Q-jets racers can use. While at Indy, some people told me that if you run a Chevy that calls for the 1.093 ( 750) carb., you can only use a 7029207 or an Edelbrock 1901. First, NHRA doesn't care about what numbers are stamped on your Q-Jet. Second, they don't care if it's a front or side fuel inlet. And third, it doesn't matter to them if it's a smog style( 1975 and later ) or the non-smog type ( 1974 and earlier). So what does all this mean? It means that if you run a Chevy, you can run ANY Chevy, Buick, Olds, Pontiac, or Cadillac from any year as long as it has the correct size venturi excluding the single booster of course. Or you Olds guys can run a Chevy, Pontiac, Buick, or Caddy.Or you Pontiac racers can run.... well you get the picture. I haven't forgotten you 800 CFM guys. The same rules apply to you. Can't find a nice core for that 70's B-O-P-C? Look no further than an Edelbrock # 1903 or 1904 which is a late smog style Chevy. When I had my Pontiac stocker I went through the barn using a Chevy carb. and it's current owner has also paid a visit to NHRA's "Party" without any problems. Hope this helps. Danny @ Q-jet Performance.

[greg fulk]

Danny I have a question for you...I just bought Bert & David Morgans 88Olds Cutlass it has one of your carbs on it.....is it ok? It has the 307 olds roller motor.........but now that that i think about it i guess it's has to be ok it just went tru the barn friday....

[Danny Ashley]

Greg-
Congratulations on your new car's successful visit to the "barn". Looks like you did good buying the Olds.And speaking of Olds, I was in the barn watching when a 1972 's Q-Jet was checked and it was an Edelbrock 1903 or 1904 which is a late model Chevy style. The Tech guy that was checking carburetors told me he used to work for Magneti Marelli Powertrain which is the company that made the Quadrajets for Edelbrock. So I guess he should know his Q-Jets. And yes the carb went through. If you need anything just give me a call. Danny

Hi Danny,

Thanks, for the update and hope you are doing well...See your old car won class..I will be talking to yah later.... Dave...1033/stock(RV-455)

[RocketBlock]

Danny,
While you are at it, could you clarify to the best of your knowledge what is or is not allowed as far as booster modifications to Holley carbs, specifically the 3310 type used on Ford and Chevrolet products?
If not you, anybody else? And could you say what the CFM differences are by swapping boosters on a Holley while remaining "legal"?

[Danny Ashley]

Rocketblock- I can't say for sure but I would guess that you aren't allowed any modifications to the boosters . I believe the rule book says you can change fuel flow but not air flow. But don't hold me to this. Travis would be the one to ask when he returns from Indy. Danny

[Lynn A McCarty]

Danny,

Thanks for the warning. I know you are just the messenger here, but I have to say that I would think that since this is technology developed by Pontiac, then a Pontiacs should be able to run it under the current rules. It is another example of how when technology developed by Pontiac is an advantage, it is either taken away or given to everyone for free. Unless of course they want to give us 20 ccs over stock intake runners, after market Pontiac blocks(so we can chop an inch off our decks), correct our piston weights, correct our rods spec, approve Edelbrock head replacement for hypo heads, and allow us to swap similar casting numbers while using the larger approved volumes. We gotta make up the disparaging and bogus rules some how. Thanks again for your report. Would you please post your number?

Lynn

[Danny Ashley]

Lynn- My shop number is 765-674-5102. I'm there from 3:30 to 7:30 M-F. Danny