I thought about checking for a snap ring but in looking at lifter and cam sites it apears that solid lifters also have a snap ring. Maybe you can shed some light on this fact. Since the motor has not ran for a few days I would think that the oil back pressure is zero and that I should be able to compress the lifter. I know on a motor with many miles I have adjusted the rockers and was able to compress the lifter by rocking the rocker. Another question would be is even on a high performance lifter is the spring at the bottom of the lifter body the same Lbs. spring as a stock lifter. All this seems thivial but the only alternative is to pull the intake. yuck...yuck!!