273 commano on the dyno wooooow

Hmm. are you sure this makes 450 corrected horsepower?

That's over 1hp per litre with a flat tappet cam, dual plane manifold, factory heads and bottom end.

I would say 350hp would be a remarkably stout high performance street driven 273ci engine. 450hp fro 273 cubes would be race car fantasy for most people.

It is a race car engine with pretty tight rules like ported stocker with stock valve size, I bet lots of compression and cam.