I have a b1 block with p72 head, ls crank with scat hbeam rods and gsr p72 pistons 81.5mm, im wanting to go all motor stage 3 cams but i dont know which type of stage 3 cam to go for, the lift is what im confused about. How do i match comp w piston to cam, or am i talking out of my *** and just get a stage 3 coming

 

First; What work has been done to the head? Is it all stock?

 

Head is being ported and polished and resurfaced. Block has been resurfaced and sleeved. Bored out to 81.5

 

Has the valve-train been upgraded? Springs, retainers, valves, valve seals, valve guides, LMA, etc?

 

No

 

Then I would do some ITR/CTR cams or perhaps a Stage 2 cam.

 

Without changing the springs and valves? Or can stock valve train with stage 2cam work

 

For a stage 3 to be fully optimized, most CAM companies recommend a fully built head w/valve train upgrade. You can get away with a stage 2 cam with just upgraded springs and retainers. But since you're going to be stock, your best bet is ITR/CTR cams. Once you boost, upgrade the valve train and go with the stage 3 cam. For now, build the bottom end, upgrade the springs and retainers and you'll be able to rev out to 8K no problem (provided you have ARP rod bolts and head studs).