I have a 311 with a victor jr intake, an original lt-1(70's) cam, the cam specs are 317/346 duration and .458/.484 lift, and centerbolt heads off a caprice cop car. My carb is an edelbrock 650, had electric choke, and its been takin off. I know the parts dont match, and all my power is above 3500. The carb is too rich down low, up until 3000 rpms, and too lean up top, around 5200 rpms, and i get alot of lean pop up top.

How should I go about leaning it out down low, and making it a lil more rich up top? Also, what is the part number for an edelbrock 650? I havent found too much info on them. I have a tuning kit for it, with a few jets, springs and metering rods. Thanks for any help.

-Justin

 

Either look at your manual or go to the Edelbrock website, they have it online. You want your cruise/power modes leaned out with smaller jets and your secondaries fattened up with bigger than stock jets. A lot has to do with your elevation too. PM me And I can help you get it tuned better in more detail.

 

Changing the metering rod step up springs will leanout the idle a bit. use a lighter spring ( lower vacuum rating)
The top end popping sounds more like over advanced timing or lack of fuel delivery at high rpm.
Most stock distributors have to much mechanical advance built in. Shortening the advance travel will allow more initial timing (14-18+ degrees at idle) for the big LT-1/Z-28 solid cam while maintaining proper total timing (32-36degrees at hi rpm)
Test the fuel pressure while running at WOT high rpm.
Anything below 3 PSi is susupect.
Could be weak valve springs too.