tti or schumacher headers ? opinions plzz

383 B block, I'd go Schumachers "Tri-Y's" all day long............. -They fit well in the A bodies without ANY fuss...... And for what I know of them STAY.. I've had and heard others with issues of the rest coming loose and always needing a header gasket..... (I don't understand why if torqued right) but, those I know with Schumachers Tri-Y's have not had any trouble with 'em!

The thing with Schumachers Tri-Y's that I don't understand is why they're rated to 500 (550) HP....... Just not big enough or what?