[USMC302]

Piston to valve clearance almost has nothing to do with max lift. When the cam is at max lift, the piston is down the bore. You should be concerned with duration and the cam timing itself and even moreso, the size of the intake valve. I had GT-40's with 1.84" valves and I was running a Comp XE270HR with .544" lift and stock pistons. I had .130" of clearance on the intake and .145" on the exhaust (in other words, I wasn't close to being in danger).

TFS Stage 2 is an advertised 236/248 duration at .50
The intake valve on the AFR 165 is 1.9
He said he would also like to run RR's.
You had .130 and .145 left for clearance with stock RR's(cool)
If he runs 1.6's he will be at .574"/.595" of lift on stock pistons with the stage 2 cam..
FORD recommends .100 and .125 of clearance.
What would his clearance be now?

Just suggesting being safe than sorry. Do you think he'd be safe to run that on stock pistons? Trickflow told me to go with the stage one until I got them notched.

Thanks