Carb size ?
 

A max size carb per rules for each motor combo. I know we no longer need carb numbers to be correct per engine. Any rule on how small a Qjet you can have? Asking to try a small cfm if legal.

Re: Carb size ?
 

Carbs still need to be the original Specs/Dimensions including boosters/Throttle blades. have

I prefer the Edelbrock Replacement Q Jets.
I have several in great shape and even NOS.!

I believe a 750 must replace a 750
and 800 replace a 800.

You can easily look down the throat to see the difference.

Believe it or not = I used to race a National Recording Holding 86 Ram 100 with
a Q jet.

Re: Carb size ?
 

If you are still running the 307 roller combo, you must use an 800 CFM Q-Jet. Plus .005 or minus .015. Same carb that I have to use on my 301 Pontiac.
Just a bit of advice, don't listen to what some "previously employed by NHRA" people might have told you.

Re: Carb size ?
 

Yeah, I wish that this were true John but look at all of the replacement Holleys that have "down-leg" boosters. The only thing that matters anymore is throttle bore and venturi size.

Re: Carb size ?
 

Thanks for the response. Saves my testing that idea.

Re: Carb size ?
 

Check your PM please

Re: Carb size ?
 

Really?

Glad I still have a lathe and my moto tools

Does fuel inlet position still matter?

I think we are going to find a tenth!

Re: Carb size ?
 

Not since they let the Edelbrock Q-Jets in.

Re: Carb size ?
 

I did not know that. I know several guys who used a 207 carb in place of an 800 late model
I assumed the rule was kinda like .030 over, vs. .080 over.

How's that "no tech" working out, again?

Re: Carb size ?
 

Thanks .....The price just doubled on all mine =
Better than the Stock Market!

Re: Carb size ?
 

Careful though. I slowed mine down .3 doing that in the wrong area.

Re: Carb size ?
 

Thanks Dave:

Fortunately I have almost 200 Thermoquads on the shelf. Plus
25 Q Jets.

When my son Jon was about 5 = I gave him a big high sided
garden wagon and a Wallet full of $5.00 Bills when we went to the
Pomona Swap meet every month. Then he would spend the weekmend
trying to buy every Thermoquad he found for $5.00. A few of the
Mopar racers on this site still remember seeing him every month and selling him a few.
He is pretty familiar with them by now 25 years later.

Re: Carb size ?
 

200? Wow , I was considering myself kinda lucky having 5 virgin Holley boosters. That's after I've ruined 2 already, they M i g h t be saveable.

Love that story.
Curious, I know the primaries are small, are TQ's very good on fuel mileage? Without getting driveability issues?

Re: Carb size ?
 

For a carb and not FI they we pretty good on MPG for
the 70's. If you got the rear Air Door adjustment dead correct
they were pretty fair on drivability. However not so much the
71 first year versions only 340s. They were recalled and replaced
with the different metering 72 version for drivability issues=
Although I prefer the 71 for the race track if can find them and
the unique jets and other stuff.