i had comp cams 818 sbc lifter with comp 943 springs and .675in .645ex lift cam with 1.5 rockers. these lifter had dyno time and 8 street miles. it was idleing and broke at idle. the way it looks is the lifter broke in the middle of the shaft for the roller wheel. so i rebuilt engine and threw it up for a loss. the other day i was looking at those lifters and noticed a few more were missing the c clip to hold the roller wheel shaft in and the shaft was almost out. could this be what cuase the lifter that failed to go bad. i was told by comp i had 245lbs seat pressure and those lifter were designed to hold 230lbs(i call bs on that).just curious what could cuase the problem.