422 dyno fail
While the combo is far from optimum....... the numbers are ridiculously low.
I’d have to see a dyno sheet from this motor along side a sheet from a better performing streetable stroker, off the same dyno, before I’d condemn it.
I agree with the OP in that I’d have expected 500tq/400hp to be “easily attainable”.
I’ve never run a port-o-sonic on a SBM, but it would really have to suck to be “the problem” with this build.