opinions welcome on build.

Frankly, I’ve never seen an instance where making a small change to the stroke, and it’s accompanying change in displacement, with NO OTHER CHANGES, has much affect at all on where the peaks occur.

Build a 10:1 387 with bowl blended RPM heads and intake, and enough carb and cam to peak at say 6200.
Swap out the rotating assy only, retest...... it’s not like it’s going to peak 500rpm lower.

Tq/ci would likely be very nearly the same, hp/ci would go down....... but the hp number would still be higher.