Dyno numbers can vary a bunch, so I'll quantify my guess by saying its what I'd expect to see out of it if I ran it here.

I've only tested one motor with a 337 on it, and it was a completely different beast than what you built....... So I really don't have a handle on how that will behave in the upper rpm's.

If it had something like a 440-2 on it, I'd expect it to get into valvetrain instability before the power curve reached its natural peak(where it would peak without valvetrain instability issues).

I'm basing that on your 928 springs being installed at 1.950.
Those lobes, 1.65 rockers, that spring set up at 1.950........ I'm thinking something will start to show unhappiness by 6500-ish, and I think the combo would likely peak a bit closer to 7k if everything is good.

I'm not suggesting you change anything......At this point, just run it and see what happens.


All that being said, I'd be looking for 625-640hp or so...... And 550-570tq with my 2-2 1/8 x 4 dyno headers.