mate off mine works for proenginebuilders in au he knows his stuff about all racing parts. and the best shells are from orginal manufactures. even if you look at a standard bearing compeard to a race their is a full ring oil track compitions dont only have a half oil way track. + race ones have one stage off tempering taken out off the construction prosses. witch result in higher temp riseing and shorting the life off the oil. standard nissan bearing are the best in his opinin. acl is a spurious part after all. tomei engine builers use orginal bearing!!!