I have a 1986 Camaro IROC Z with a TPI 305. The 305 is tired and I want to build a 350 to swap it in. I plan using the top end from my 305 (heads, intake, fuel system) and using a rebuilt bottom end from the new 350.

In my area only one Junkyard had any 350s before one piece rear main seals. I haven't got a price quote yet but the guy believes both had blown head gaskets and there is water in the cylinders. I plan on getting any engine I buy machined (maganuflex, etc). Would these engines still be worth possibly buying?

Also in my area a private seller has a 1986 350 block for sale.

I want to keep this build as cheap as possible. I plan to use Summit Racing's own rebuild kit. My only problem with buying the 1986 block is sourcing a crankshaft and connecting rods. I can't seem to find stock replacement crankshafts or connecting rods. Everything is performance.

My only problem with the 89 and 93 years is the roller cam. Roller cams are better performance wise in the long run but finding a stock replacement cam is impossible Every cam is performance only. I can find stock replacement flat tippets easily.

What do you think is the better option? Any advice would be appreciated.

 

Not an "Advanced Tech" topic. Let's move this to the 3rd Gen forum, to increase chances of a response. Unfortunately, not a lot of 3rd Gen folks here any more, mostly 4th Gen, LT1 owners. An alternative would be:

https://www.thirdgen.org/forums/

 

Just because the newer blocks can use a roller cam doeant mean you have to use one. You can stab a regular cam and lifters right in. Just make sure you use the right push rods. Roller ram push rods are shorter.

Any reason you are wanting to keep your 305 heads. They will have smaller valves, But That can help throttle response. Also have to check where you want your compression ratio at as the 305 heads have smaller chambers and will raise compression on a 350.

Anything like emissions testing affecting your cam choice?