Small block bottom build horsepower limit

Jax said
Well the goal is for a 600-650 hp engine, mostly for drag racing.

I recommend to watch the David Vizard Powertec 10 youtube video on the 1,000HP SBF block modifications. The same shop can/will do the same on other manufacturer blocks. Doing this on a SBM would allow a safe 700HP stock block to run reliably.