I recently purchased and put in a big block 454 cubic inch engine in my 1978 vette. It was previously in a Nova and used as a drag strip car. It has very little power until it reaches 50 mph then goes great. I did not change the turbo 350 transmission or converter that was in my car. The Nova had a turbo 400 transmission but did not fit in the veette. I put in a rebuilt Rochester Quadrajet, changed the wires cap and rotor and re-timed. Any suggestions?

 

Sounds like the cam used may be for a mid to high end power band.
Recheck your timing, it may a little be off.