We run nothing but Taylor Spiro Pros.Last set on my 12.5 440 went like 15 years.Still worked great but looked crappy.Oh yeah even on BBs and SBs with headers no melted boots.My kid did run a part sleeve on 7 because his 62 300s headerers were 2 1/8 and close.His were on 6 years when he sold the car.Rocky