NON_ROLLER ABOVE ROLLER BLOCKS BELOW
the stock Chevy hydraulic roller lifters , dog bone and spider springs don,t always work reliably, ALL THE TIME with engines having over .500 lift or when spun over 6000rpm, its not all that rare for the lifter ,retainer to bend the retainer spring allowing the lifter to spin sideways, in the lifter bore, resulting in a destroyed cam, thats why Ive suggested BRAND NAME ,AFTERMARKET RETRO FIT CAM COMPONENTS BE USED
roller blocks have taller lifter bores, because roller lifters are taller, and a provision to bolt the lifter retainer spring, but they can be very easily used for the earlier flat tappet lifters if desired by simply removing the spider(SPRING RETAINER), keep in mind most roller blocks use one piece rear seals
viewtopic.php?f=51&t=686BTW, , on BIG BLOCKS the oil pumps and oil filter adapters are different due to the block oil filter recess and rear seals being different
GEN 4 or MARK IV
GEN V and VI
