I just put in 350 TPI w/ vortec heads. The car won't start on first try. Well actually sometimes it does but rarely. It also idles bad. Sometimes it idles level then suddenly it shotts up a hundred rpm. It's like its coughing or something. I think it might need a fuel pump because that is the only part of the rebuilding process that we did not replace. I heard that I need to gap my spark plugs higher because my new motor is so much more powerful. Is this true? Please help me.

 

I think i would double check the timing at TDC (with a timing light), and look for vacuum leaks. Then maybe if the issue isnt resolved reset the Idle Air Control motor (follow the instruction in the tech article section).

Hellraiser

 

Make sure your wires aren't crossed. I know I crossed mine once and it ran like crap, backfiring every few seconds.

 

vortec heads + non vortec tpi base = port alignment problems????
are you using a vortec tpi base? correct me if i'm wrong here guys.