i had a cpr clutch kit with pipes hh weights, no colour on spring. the spring is a little smaller diameter, when i took my primary apart , i found that it was chewing away at the inner part of the sliding shieve, and i also hace a 911 cap on it, it was really chewed up on it. wonder what kind of performance loss you get on top end, when you put the stock spring on it slides over and loose and when you put cpr kit spring on you have to push it on, maybe no concern. also probably not as bad with stock cap, sist