what is needed to swap from a 305 to 350?? do you have to get all new wiring and computer, or do you just use the old stuff? is there anything else??

 

Depends upon what you have now.

Carb - no big issues, just tuning, mainly. If LG4, air cleaner and exhaust have to go (but that's the case if you keep it an LG4, anyway).

TPI - no big issues, if cam is kept reasonable, adjustable fuel pressure regulator helpful to aid tuning. Porting of plenum and base, and larger/shorter runners typically help. In some cases, larger injectors helpful. Custom PROM will help optimize as performance improvements are undertaken.

TBI - seems to be the most sensitive. But, many have done it, TBI forum is the right place to ask.

In all cases, exhaust upgrade is in order. Headers a good idea, and good-flowing y-pipe, cat, cat-back.

 

This may help u.
https://www.thirdgen.org/techbb2/sho...hreadid=127674