sorry but you gotta keep up i had two dunkin's this morning already and i don't stay still on the weekend.
so you used a spray? was it from POR that way or did you use a thinner and gun? (was thinking thinner could cause it to now hold up as well to heat) or was it thin enough to shoot without clogging?
the exhaust spray comes in three shades and should hold up to higher temps than the engine block paint.
but the only place the engine paint discolored on my old skylark was around the exhaust ports on the heads.