3 1/2 years and counting...they are built with the same parts as the Comp Endurex lifters and I've got some of those in sb and bb chevy's on the street. I know of at least 3 customers that have over 25,000 miles on them with no problems and no intent to rebuild them anytime soon!
I try to keep the max lift at .600 after lash and try to keep spring pressure about 200lbs. seat and 5000 open max. Works on heave bb chevy valve train up to at least 6800rpm on my dyno with 240-250 @.050 and .610 lift.
I also have a sb ford that has approx. 15,000 miles and he races it 3-4 times a year at Fontana when they do the street legal's...he runs that 347 to 7200rpm and drives it there and back home (riverside approx. 30 miles one way) and hits all the cruise nights and car shows at Pomona so...
You just need to keep up on the valve lash, and I recommend replacing springs when you see a pressure drop past 10% of where they are after dyno time or 500 miles of driving.
