rhoads lifters?

I installed a set in my M.P. 360 short block with the (.509) cam and had problems from the start,the lifters pumped up on start up and never blead back down.I installed them with adjustable rocker arms set up to there instructions and once they pumped up they stayed pumped up.The only way I could get the plunger to colapse was to remove the lifter and take the snap ring off,take the plunger out and dump out the oil inside the lifter,reinstall the plunger and the lifter would function again,meaning I could colapse the plunger again,now even with the lifters out of the engine all 16 lifters were fully pumped up and would not colapse until they were taken apart and put back together.I never saw anything like this happen before. I didn't put them back until I talk to someone at Rhoads and find out what happened.Well that's my experience with them.

Roger