I'm removing my poor old 305, as its starting to smoke on startup, and needs a rear main seal. I want to buy a short block, and use my intake, accesories, etc. I know I will need new injectors as well as a knock sensor, but what about the prom? Also, will a block out of a newer camaro work with the 85'? Basically, whats the ideal 350 I should get to make my swap go smoothly?

 

The least hassle would be to get an '80 to '85 350 shortblock. It might not be the best, though.

The only thing "wrong" with earlier blocks than that is the dip stick is on the driver's side. No problem if you have headers, an extremely tight fit if you don't. A Lokar flexible dipstick & tube have been reported to resolve that.

'87-up roller lifter blocks are pretty popular. Roller cams tend to make a little more power while maintaining manners. But, they are also more expensive, and you'd have to get a different flexplate because they switched to one piece rear main seals in 1986 model year.

The '85 PROM will be okay as long as you get a computer-friendly cam. But, it won't be able to handle as much power as the later SD, or even later MAF, systems. It'll be okay for some good power, though. Just keep the cam reasonable.

 

Ok so if I find a 87'+ short block, and bolt up my heads but keep the cam decent I should be alright? Thanks for your help I just don't wanna buy something and then find out its not gonna work

 

And keep the compression reasonable. Dished pistons, thick head gaskets, and unshrouding the valves/combustion chambers are the typical approaches when using 305 heads on a 350. I used 10cc dished pistons in my 350 shortblock, the "305" heads turned out to be 64cc chambers, with a .020" compressed height steel shim head gasket and .012" removed from the deck produced 9.7:1 static compression.

 

Mint thanks a lot