Carb sizing/choice? (and tuning..)..again..

Hey guys,
Wow that took of fast! sorry for just responding I've had one hell of a busy week!
You guys are a great help.
Some one enlighten me on the difference of Holley and Eddlebrock? Not being a muscle car guys I've never taken a look.

Don-As soon as I go home today ill measure and see what all numbers i can find on the block and heads. Hopefully this will turn out to be something good.

And as far as this experience with holleys the are a pain in the ***. Just where they put some gaskets and tuning is just strangely stupid to me.

 

Don,
It's deffinatly a 302. It measures 9 inches and the casting number on the block is c8ae-6015-b
So it's out of a 68 galaxy? I'm not sure on how to read the second half of that!
Thanks!

 

6015=engine block b=second version

 

You will be most happy with a carb in the 500 cfm range. This matches what Ford used (and they pay their engineers more than internet jockeys, I know, it's hard to believe).

The formula that works best is: no more than double the cubes. So, 302 x 2 = 604. Add in restrictive stock exhaust, and you are down in cfm. And you'll love the driveability of a carb that encourages rapid flow changes through being small enough to meter properly.

IMHO, Holley carbs are for racing. Their reputation far exceeds their capabilities. Go ahead, ask how to adjust the midrange fueling (you know, where you do the most of your driving, the midrange). That's right, there isn't any way to directly adjust the midrange. Quadrajets, Carters, Edelbrocks all use needles to directly adjust midrange, as well as jets for top end (rarely used on the street) and needle screws for idle.

So, it's your money, but it'll be your money for the fuel to run this thing, too.

Cosmo (yeah, I'd get a small Quadrajet, too)

P.S. The only real downside to a too small carb (within reason) is a lessening of outright horsepower. Mileage and driveability will not suffer, and will likely be better all-round.

 

Any brand is fine. ALL carburetors need to be tuned. Anybody who says otherwise either got lucky, or does not understand how to tune them. I'd not run anything larger than a 600, and one with vacuum secondaries, at that. For my money, I'd get an Edelbrock, but that is because I know the most about tuning them, and have had the best results with them, in street applications. If it is indeed a 302, I'd get the electric choke 500. Yeah, I said 500. The vacuum signal is better with the smaller bores, so the fuel metering, especially at part-throttle cruise, will be more accurate. I run a 500 on my 305, and it can smoke the slicks like there is no tomorrow AND turn 28.5MPG at 65.

 

Oh, and the next time you guys are using one of the handy-dandy online CFM calculators, plug in your freeway cruise RPM, instead of the maximum RPM, and see what that number looks like.

How well will your carburetor meter fuel at THAT RPM?

http://www.4secondsflat.com/Carb_CFM_Calculator.html