Vibrations / Shaking / low power

Hi @ all!

I'm sorry, but here we are very uncommon with V8- engines...

I've a problem - my 74 318 LA is running very rough. If I accelerate, it feels like the engine is shaking, it isn't running smooth.

We renewed all mountings, tried to tune the carb exactly, but it's still like an old tractor running. You really can hear every piston working.

The formerly owner told me that the engine has a 0.30 overbore,it had been completely overhauled.
The cylinderheads have been overhauled, too.

I'm running a 600 cfm Edelbrock carb on an Edelbrock intake at it.

One of our engeneers told me it would be sounding as if one bank of the engine isn't running the way the other one does.

Any ideas, any suggestions?