Make sure you double check the height ofvthe lifter cup compared to old ones. If higher or lower you might need different pushrods............from brand to brand they are rarely the same
X2 When I switched from the Morel roller lifters to the Johnson roller lifters, I needed a longer push rod. The Johnson lifter cup was .230" deeper. I went from an 8.725" push rod, to a 8.950" push rod. Not sure if the lifter cup is consistent across the Johnson Lifter line or not, but it is definitely something to check.
