How much HP and what do you think it will run.

max512wedge said
That would be nice to go that fast. Do you have a estimate of HP!

Are the heads ported ? If you have have that big of cam in the 280s at .050 I'd guess you will hit 660-700 hp is range at 6300 rpm.
Just for a reference I have 264 @ .050 in my 470 and make 675 HP at 5800 rpm