pachangalpina

Anybody know what the difference is between the roller lifters on the HP500EFI and the 502 MAG EFI?

I have been told that the HP500EFI are good for use with a higher lift cam and the 502 MAG EFI ones need to be changed if using something like the Crane 731 cam.

Breathe Later

HP500 EFI motors use the Crane gold lifters. The 502 mag /mpi motors use the stock GM stamped parts. The roller lifters require new studs and pushrods. The intakes on cyls 1 & 8 require a slight clearance grind on the Crane lifters when used with the stock valve covers. The cast "dripper" oilers on the mag/mpi motor valve covers also require removal when the Crane roller tips are used.

stevesxm

seems to me he is asking about lifters.... not rockers

Breathe Later

My bad!

The lifters are the same Crane pieces in both motors. I'm using the -741 cam in my 502 mpi/whipple motor with the stock lifters.

pachangalpina

The reason I ask is because the "blue" motors have different part #s than the black motors. The Lifters in the blue motors are also more expensive.

Crane recommends with a lift over .570 that you should change from the stock lifters. I have heard from various other sources that you are fine to .600. Since I am using the 731 cam @ .610 i have figured I should update these parts. Since the 500and 525EFI have higher lift cams, I was trying to find the difference and see if these are actually the Crane replacement factory style lifters.

Anyway, I decided to use the retro fit style lifters that I have access to.

Thanks, Todd

PPlay33

The blue motors come with Crane roller lifters, and the black come with GM lifters. The black motors will make .600, but I would put the Crane lifters in with the Crane cam. The GM lifters are very reliable,but their retainers are hit by the lifter body over .600 so be safe with the Crane.