I've disassembled my SFT EDM lifters and it is an empty hyd lifter with the DDM hole on the face. Lifter body, cup, and snap ring. The OEM hyd roller needle bearings are splashed oil as far as I can tell. I'm not sure how they would hold up with a solid roller. A tight lash SR might work. I'm on the fence about sticking with a SFT/EDM lifter or spending the big bucks for a SR setup on my street strip motor.