Which head/combustion chamber is better for performance? Speed master aluminum LA or aftermarket magnum iron head?

[33IMP]

I like the idea of a 451 or 470 BBM stroker, but I have never seen a SBM over 450 cubic inches. Your response reminds me of the guys I worked with whom would die on the hill of technically quoting documentation in arguments. You are absolutely correct on max effort, but I didn’t spell out ‘typical’ max effort on FABO here-doesn’t matter, you made a point.

As for a tow truck cast iron heads for stock stroke, and if you stroked the motor to the 408/410 .030”/.040” maybe the speedmaster heads.

I have a bunch of LA blocks, but if you don’t have a block, go magnum, with roller Magnum Valvetrain and never look back for your towing application.

An acquaintance of mine had built two big small blocks.
His first was a 471(r block, I believe) with some sort of W head on it.
It was a street driven (frequently) 71 demon, nine second car as it drove in the gates, cover car for a couple mopar magazines. I beat him once, heads up, with my Cortina, but I had to red-light to do it.
His second one was a 501 (or 502, I've heard both). Just a bit too far over the edge, and a little too weight conscious, Too many light parts I heard. It made impressive power, but it didn't last
He drives a hellcat demon one seat now.