The car accelerates fine at partial throttle. At WOT, it pulls hard but has a "sputter". Also an occasional small backfire happens. THe engine runs great otherwise. Edelbrock carb and manifold if that makes any difference.

Not enough fuel? air?

[QUOTE=71Shark]Not enough fuel? air?[/QUOTE]

That was my thinking. Maybe I need to go one size bigger on the secondary jets? Tell me if I'm waaaay of base here...

Just a bit info needed......

Probably really draws the air with those pipes if they are open - virtually no back pressure.

[QUOTE=Falcon]Just a bit info needed...... [/QUOTE]

1. New carb and intake that came as part of the engine purchase. Problem has always been there, just procrastinating doing something until now.

2. New carb (or at least fairly new - around 6 months old). Problem has always been there.

3. Not a new problem

[QUOTE=71Shark]Probably really draws the air with those pipes if they are open - virtually no back pressure.[/QUOTE]

I bought the engine as a turn-key engine. It was tuned and broken in (of course, not with side pipes - just regular headers).
jgoglick2007-05-27 17:37:15

Sounds as if it's running out of fuel @ higher rpms. What type of ignition is on it now? What kind of fuel pump? How much wood could a woodchuck chuck if a woodchuck could chuck wood?
Check the fuel line from the chassis to the fuel pump for kinks. You might wanna put a fuel pressure gauge on it temporarily to see if it's loosing pressure at the time it starts bucking....really sounds like a fuel issue, but could be ign. related, too.

Here is a link to the fuel pump I got. It has an HEI distributer. I'll check for kinks in the fuel line. Oh, and he's chuckin about a cord an hour - he's fast!

Do you know at what RPM the problem occurs?  Sounds to me like it may not be getting enough advance.  Do you know how much timing you have "all in" (>3000 rpm)?  I agree, it may be mixture related too, possibly due to the pipes.  These things take some effort to tune.