Carb or timing issue?

I have a late 70's SBC in my truck. Just had a new timing chain, new gaskets and mild cam installed. It has an edelbrock performer carb, new plug wires etc, etc. Engine just doesn't seem to have any punch. From an initial stop it doesn't accelerate well. Just from a stop it will pop through the carb. Gradual acceleration is fine, no popping. Just feels flat. Idle is fine in park and in gear, just no power. I'm going to check the timing tonight. Maybe it's out because of the cam break in. Kind of puzzled. Any tips would be great1

Welcome to the site –I’m just down the road in Portland and have among my collection a 1971 Chevy ½ ton, 350, automatic, Edelbrock Performer manifold, Hooker headers and an Edelbrock carb. I have the 1806 Thunder series, but they all seem to have the same problem out of the box – they run rich.

I had to go a size leaner on metering rods and jets to get decent performance.

The popping sounds like you’ve got a bit of a timing issue. I’m running a stock HEI with 8 degrees (initial w/vacuum disconnected) and it runs fine. The cam break in should not have had any effect on timing, my guess is that you may be off a bit.

What cam did you install?

Did you do also install new lifters?

As a final note – if you replaced a well tuned and working stock 780cfm Quadrajet with a 600 or 750 cfm Edelbrock on an Edelbrock Performer manifold, you may get a bet better mileage but you will not have the snap the Q-jet provided. There’s a lot of disappointed folks out there who have replaced Q-jets only to find out they’re not such a bad carb after all - in fact, one of the best factory pieces to ever come out of Detroit!

If you have an Edelbrock Performer RPM manifold and an Edelbrock 1413 you’ll get some real good 2500 – 5500 performance (depending on your cam).

Give us a bit more information and I’m sure you’ll get lots of help.

Regards,
Glenn