How about the .842 268 Voodoo vs the .904 268 Voodoo...... in an 8:1 360 with stock 1.88 heads?
I doubt it would even be 6-8hp.
But...... until you actually do the test...... you don’t really know.
What I do know is that several of the milder cams recommended in this thread would fulfill the OP’s requests, with the least amount of additional parts & labor required to get it all up and running.