I've been kicking around the idea of switching to solid roller lifters in my 03 5.9 block (408).
Got the IMM 2.02 heads with beehive springs. Cam is a custom CompCam with 236/248 duration and 571/584 lift with 112LSA..blower cam. Not sure if I would need to change the springs for higher pressure ones upon using solid lifters. From my understanding I would need to.... but wouldn't be exactly sure what spring pressure I would need.
Sometimes think I hear a little rattle of the hydro lifter upon start up. Has adjustable rockers on it. Tightened up the preload a little but still does it.
The Hughes retro roller lifters has been working good in my LA 360. Good oil pressure and no ticking. However at first I had a lifter not pumping up in which after taking the lifter apart the manufacture forgot machine around a small hole inside the lifter.
Hughes "retro fit" lifter not pumping up!