15W50 was a smart choice, I'd steer clear of M1 oils for street cars, they took out too much of the good stuff, even the holy grail 0W40 isn't what it used to be...
I'd also look at Redline again if I were you, oil temps in excess of 250* are rough on "fake" syns.... I'd want a REAL synthetic oil in my pan taking that kind of beating...
