at the lip or the ribs?
are they smaller than the Mach 1 alt pulleys? my old stock Mach alt pulley measures 2.75 at the lip and 2.5 at the ribs. if his is 2.5 at the lip he could be over-spinning it, assuming they are supposed to be the same size as the Mach 1.
You can. But expect a CEL at the very least. And possibly the computer going into some kind of limp state.
What else besides knock sensors can pull my timing so low?