New setup- 340 based 416, 360 based 387, or 360 based 408?

Duration @.050 of 260+
My 408 with same heads ported only makes 520ish hp with a 246/250 roller @ .648 lift
But I only have 9.8:1 compression .
Dynoed at 493 but I found I had 2 qts too much oil and #7 valves were way too loose .
Figure I picked up 25 hp correcting those items .