FtrSpeedy

Ok first gear hammer down shift at 5k, hard thru 2nd gear hit 4500 (about 80mph) engine just stalls for quick sec then misses and jerks around, shift into 3rd same thing at about 80mph. Ive tried 3 carbs small medium large, replaced plugs distributor brand new and tried 3 sets of blue max plug wires. Check valves repeatedly, this last time i hooked up vac advance set timing to total 34 degrees, 2nd gear couldnt get past 3800rpm. Im stumped, anyone got any ideas? Thanks for your time.

Edwardgp

If it was my car I would be looking at the valve springs and push rods.

FtrSpeedy

What would be wrong with the pushrods?

Edwardgp

I would just check them out to make sure they are not bent, I was thinking the way it is acting that it might be an issue with the lifters, push rods, or valve springs.

mjwadams

I would tend to agree with Edwardgp. The pushrods have a lot of reciprocating mass which effectively limits RPM. That is why OHC engines usually have higher red-lines than OHV ones. Your valve springs are what controls this mass and keeps the valves from hitting the pistons. If they are worn, it can affect the timing, more so at high RPM. You can also grenade the motor, same as if the timing belt breaks on an OHC motor.
I would keep it below 3K until you checkout the valve train.

FtrSpeedy

Ok ill check it out. Thanks for the tips.

FtrSpeedy

Fuel pump is bad.

Edwardgp

Let us know if that fixes it for you.

FtrSpeedy

It is confirmed, mechanical fuel was bad, engine runs awesome now.