Highest flowing sbm heads?

B3422w5 said
260/264..flat tappet..565/565 lift
106 in at 104
convertor 4900-5000

Don, I had a very similar grind in my 408, 260/264, .626/.633 IIRC with 1.6 rockers, in at 104°. It was only 10.8-1 and ran 6.57 @ 104 at 3340#.