you can stay w/ that or try something else, in my 94 LT1 i've tried Redline 10W-30, 5W-30 (it liked), PP 5W-30, M1 10W-30, 5W-30, never could find GC around here.
MaxLife 10W-30 is in now and it feels good. wallet feels good too, $13 jug at walmrt. think i'll try their 5W-30 next