You don't "re sleeve" a chevy engine. The cast iron cyl walls are more than strong enough for 800 + HP
The idea is just not to bore them out too much and make them too thin. .060" over is max over bore. At .040" have block sonic tested to see if it has enouh wall thickness to go .060"
You don't use high compression, and supercharger. In fact you want lower compression with a blower or turbo. The boosted engines I build, I run 7.5 to 8.5:1 compression then run 7-20 psi boost depeding on type of forced induction and setup.
You eaither build a high compression NA engine, or you build a lower compression forced induction engine.
My engine in my camaro is NA, 10.34:1 compression, 600 HP. The engine in my dad's firebird is a 8.3:1 compression twin turbo'ed engine running 12 psi boost, making 700 hp
Both are built from core blocks. Mine is a 1971 350 block, his is a 1969 327 block. Both came from a junkyard. $150 each for the core engine with intake down. Everything was took off and scrapped. The only parts we reused was the blocks. Had them hot tank cleaned, bored and honed, line bored, decked. Then went with aftermarket crank, rods, pistons, heads, etc
You don't 'need' a new block. 90% of all performance engines, hot rods, etc that people build, starts from a good junkyard core block that they have machined.
The only new chevy 350 blocks that are being made is by GM performance parts for use in their crate engines. Check with GMPP, jim pace, SDparts, etc.
Other new blocks are aftermarket race blocks for 1000 HP builds like the brodix, dart, world blocks
Summit racing and competetion products sells ready to build 350 chevy blocks but they aint new. Its just a core 350 block thats been machined