After doing some exhaustive searches I am still curious as to what the valve train criteria are for moving to a Comp R (Pro Magnum) Lifters.

Current Valve Train Specs
Cam: Comp XE 230/236 cam (3315/3316 lobes), 545/544 lift, 112 LSA
Springs: CC 985, Seat 140 lbs, Open (.550) 330 lbs
Retainers: CC 740 Steel
Rockers: CC Pro Magnum 1.6 ratio
Pushrods: stock (94 hardened)
Lifter: OEM Replacement

This motor is making respectable power and runs out of steam at about 6150 rpm.

I am considering upgrading the lifters to Comp Rs and I was trying to determine what the criteria are for upgrading the lifters? Is it strictly a function of RPM or do seat pressure and other factors figure in?

What are the advantages of running an R Lifter when the situation calls for it?

 

you'll most likely be just fine with stockers.

 

I think someone once told me anything over 350lb. open pressure and you should use an R lifter.

 

I've used stock lifters with more open pressure then that with no problems, I have 400 pounds open pressure so I used comp R's, if I could get away without using comp R lifters I would, too much of a paint to setup etc...

 

Your stockers will be fine!

 

OK, OEM lifters may be fine for my set up but I would still like to know at what point a Comp R lifters would be recommended.

I have not been able to determine the criteria for moving to the R Lifter. Is it a function of seat pressure, RPM, cam profile, or other parameter, or a combination of the above? I understand that my setup may not warrant R Lifers but I really would like to have a better understanding as to why, as I may be moving to another cam in the near future.