Any idea what the typical DA is where you race?

And for those keeping score....... I didn’t port Ricks heads...... I repaired them.
They were suffering from the “not all that ususual for stage 6’s, the valve seats are loose syndrome”.

They’re std port stage 6’s with similar flow numbers to BradH’s old 6’s.

I’d probably lean towards to low deck 511 build myself.
The 400 block is generally tougher and that combo can use a std RB intake manifold.

Flat tops .005 down the hole and .040 gaskets, heads at 72-73cc, would put it at right about 12.5:1cr.

I’d probably open the heads to MW size and run either an Indy 440-3 or the Edelbrock SV.

Put enough cam in it, should work pretty well.

That being said....... if it were in the budget, better flowing heads wouldn’t be a bad thing.