ZsTransAm

hi, i bought this car about a month ago and its my first carberated car so i dont know a whole lot about carbs. its a 5.0 with accel ignition (like MSD) and a 4brl edelbrock 750 carb. ive had a couple people tell me that that is big for a 5.0 and id like to know if they are right and why. would having too big of one actually make me loose power? should i think about getting a smaller one? i know a guy with an edelbrock 600 he said he would trade me, but is that too small? thanks alot, and sorry for all the basic questions

ScottyRS

iTrader: (2)

A 600cfm carb is usually ideal for a 305 engine. They don't require as much fuel, and the 750 is way too much. With the 600 you'll probably notice better gas mileage, better throttle response, and better all around performance.

camarojustin

, do the trade

Rick King

to big for a stock motor unless u jet it down, but to complicated for a daily driver

later and

GB

rk

F-BIRD'88

The 750 is not too big. The stock QJET than comes on stock 305's flows 795cfm. A airvalve/velocity valve type carb like the edelbrock or Qjet automaticly "sizes" itself to your motor's airflow needs.

You can fine tune your carb to improve fuel mileage and throttle responce using edelbrock tuning parts. Jets rods and accelerator pump squirters.

I find the 750 edelbrock is a better carb than the 600 reguardless. Stick with the carb you have and fine tune it. the 750 will make more power on a 305 then a 600.

What intake manifold are u using?
assuming you have the 1407 model 750 and is has stock out of the box jetting:
Start tuning by changing the primary jet from #113 to 110
change the primary metering rod form #7147 to 7547
This will tame down the primary side for improved mileage.

You can read further on tuning your carb here:
Volvord 784VC Edelbrock Carburetor

BlkBird408

I agree. I think the 750 will be fine as long as you tune and jet it down as described above!

ZsTransAm

about how much power will this carb give me over the stock carb and can i expect an even better power gain when i get my midlenght headers installed because i have an upgraded carb ? thanks again, and im planning to stick with the 750 by the way

five7kid

iTrader: (14)

It won't give you any more power than the stock carb is capable of providing. That's a common faulty thinking pattern that the stock carb must be holding back power. It just isn't true.

It also isn't valid to compare a q-jet that can flow over 750 CFM working fine on a stock 305 to how a Performer 750 CFM will work on a stock 305. The q-jet has small primaries that will accomodate most any displacement. WOT flow is provided by large secondaries that will feed a pretty big engine, but is controlled by air valves that keep the carb from overwhelming a smaller engine.

The Performer carb, however, has larger primaries and secondaries for larger flow models vs. smaller flow models. Yes, they have an airvalve type system on the secondaries, but larger primaries will reduce part-throttle air flow speed for smaller engines vs. the same carb on a larger engine, which reduces booster signal and therefore throttle response and to some degree fuel economy. The larger carb might have slightly better WOT power, but you have to decide which is more important to you - fuel economy and driveability, or WOT power. (The q-jet is probably the best choice for both of those, by the way.)