350 SBC 4 Bolt Main 800 to 1000 HP

[MonzaRacer]

The best defense is a good offense. to prep a stock block for high power under boost you cna buy a Motown block.
On the street with turbo AND the violence of NOS would split most stock blocks unles tall filled with hardblock.
ok an 010 block (last 3 digits of casting # )from 79 will have the small pad under alternator and I would not push a thin wall block much past 600 hp and thats a stretch.
They can take some abuse but just dont have the stability for bigger power.
If you want to build a big power engine use older 2 bolt blocks, splayed caps and look for the 010 020 inside the timing cover area, this is the tin/nickel content, if it just has 010 and no 020 it only has tin and is not as hard.
My preference would be an aftermarket block for anything over 800-850 hp .
you can make better power with aftermarket blocks and better reliability. Stockers just wont handle the stress. Trust me on this.
We had a 380 in stroker (4.125x 3 5/8) 18 degree Brodix and when this one was built no one had done it yet and cost well over 20K and the engine split cylinders even with hard block, BUT we picked up 68 hp and 53 lb ft of torque by going to GMPP CNC block and both had imperial roller cam brgs which is a mahot pain in a stocker.
we gave CNC block a .003 shave and bored it for cam bearings and finish bored and honed with cork bond stones for the super slick finish. ANd it really makes the car it presently in run VERY good.
Good luck.
Lee