[pastry_chef]

Originally Posted by Tim Corcoran

Dave at SD performance has done some testing in this area and you can read about it on his website.

Yes and I've commented on it several times, obvious mismatched combo.
REVERSION MONSTER.
It does not take 263/271 dur. @ .050 to make 502 HP with headers.
A single pattern UD solid flat 246 @ .050 will get it done.
Not an analysis on LSA.

467ci 9.5 to 1 OEM D-port headed engine in which we were running an Ultradyne Solid Flat Tappet cam with 263/271 dur. @ .050 on a 112 lobe sep, the engine made 502hp with 1 3/4" Hooker SC headers when we switched over to A-body Ram Air manifolds, peak hp dropped to 457hp and at 6000rpm we saw close to a 75hp drop, obviously this combo worked much better with headers, the reason being that this particular camshaft has a lot of overlap and needs the long primary tubes of a tubular header.