Here's some advice a friend gave me (not that I can actually take it due to lack of funds.)
"the block to have-70s C/K series 4 bolt main high nickle 3970010. This casting is also in camaros/vettes as 2 bolt mains.
you get ahold of one of these bad boys, theres no worries of block cracking or grenading at 500+hp.
the heads that flow are any double hump pretty much. 461 461X 462 292 291 186 187. Make sure they have 202 intake 160 exhaust valves. (they have bigger ports to begin with) any X code head=factory high flow. (some aftermarket heads dont even flow as much as X codes) Angle plug heads are typically over the counter back in the day aftermarket GMPP. those are worth BIG bucks. I know im not mentioning the power pack 283s, or LT1 350 (1970) heads. Those are a needle in a pile of needles to find. I have a set of power packs on stand by but too much compression due to small chambers id need to run 112 race gas with -12cc dished pistons.
If you cant come across those heads, Bowtie Phase 2 or Phase 3 heads.
If you do come across those heads, take them to a machine shop to have the rocker arm studs removed. Theyre factory pressed in and a bitch to get out. Have them removed and tapped so you can have screw in studs. Pressed in ones can from high rpm and vibrations caused, back out and ♥♥♥♥ up your valve train quick. rounding off cam lobes, bending valves etc.
crankshaft. You want to find C30 C40 C50 C60 trucks, dumptrucks, tow trucks. Some were equipped with 327s and 283s. Youll want the 327 crank. And if your racing, and regulations are 2bbl, youll want the intake (2bbl high rise) These cranks are steel, and nitrded. Take the crank and rotating assembly to a machine shop, have them lighten it, knife edge the counter weights, chamfer the oil holes. When you knife edge it, you are going to reduce the turbulance in the crank case which means less oppsing force on the crank at higher rpm. Your going to need your entire rotating assembly balanced. Pistons rods crank balancer and flywheel.
chamfering your oil holes will increase oiling to the bearings.
thats really all you have to know. That and what cam you should use. depending on the application, there is a such thing as TOO much and it can hinder performance."
Does this seem reasonable? Sounds too good to be true, help me almighty Chevy god.