Ponyxpres

I have an 83 5.0. I bought it about 6 months ago and it had a 600 cfm holly. Therest of the engine is stock.I have been told this carb is oversized for the engine. I run a little rich and I dont feel that Im getting the power I should. What is the best carb size for the engine? Anybody?
Thanks alot!

Colorado_Mustang

600cfm is fine for a 302. You just need to tune it up a bit.

67mustang302

Stock 302's don't need a 600cfm, but it's not too large if it's tuned right, especially with a dual plane intake. Remember that if it's dual plane, the divided plenum will onlly allow any 1 cylinder to use half the carb, or 300cfm.

http://www.corvetteactioncenter.com/...ools/carb.html This is a really good carb cfm calculator that I like, it takes into account VE and manifold type, and gives you a range rather than a straight cfm number

Ponyxpres

Thanks for the info guys....I do have a dual plane intake.What kind of tuneups for the carb? Jets? Anything else?
Thanks again

Colorado_Mustang

Jets, accelerator pumps, squirters, power valve....don't forget about the ignition system (plugs/wires/cap/rotor) as they can also make an engine seem to run rich.

Get a book on tuning Holley carbs. I have one by Dave Emanuel that has good information. There are others out there that will have good information as well, however. A rebuild kit may be a good place to start if the carb looks at all dirty.

Ponyxpres

the carb has been rebuilt. I have good plugs, wires, and cap but I want to upgrade my ignitioncoil. I have no idea what to get. Any suggestions?
Thanks

Colorado_Mustang

I like MSD products. Some like Accel. Others like Mallory. You honestly can't go wrong with any of these.

Ponyxpres

thanks alot for the input guys

johnnyhou

HEY wait, might have a blown powervalve. Might should replace it with one that is rated for the vacuum that corresponds with your cam.
Ive built engines that pull alot less vacuum that stock and have had to change the powervalve in holley/demon carbs to suit the cam.