I plan to rebuild my 305 soon in the winter. I want to increase HP to above 300-330 . This my plan so far. Getting a 350 block and porting my 305 heads with better springs and rockers, better cam. porting my intake and matching. porting my slp runners. and headers. Is this possible and how much horses can i get out of this? I just dont know what cam to get and rockers and springs.

 

i'm no speed junky by any means, my 305 TPI with 200K on it still has enough pep for me. But i've done alot of reading and pricing and would recommend doing the following if you're trying to get less than a HP/cubic inch. shouldn't be too hard with:

the stock 350 block that you're already getting, preferably a 4 bolt main.
instead of porting/polishing the heads spend the money on better flowing heads, i would say vortecs but the intake is expensive since you're still going to use the TPI.
CAM. Get the air in/out of the block better. You didn't mention anything about getting one.
Exhaust - big gains can be had with headers and bigger tubing and muffler.

not too mention the reprogramming that would have to be done on the 305 computer.

that's my $.02. If nuthin else at least your post gets bumped.