Coil bind is the big problem.

If you don't know the cam lift you have to measure it.

With a dial indicator set on the retainer - Zero it out at either max lift or when the rocker is loose and see how far the cam is moving it. Take that number and divide by 1.5 Then multiply by 1.6 and see what your lift will be.

With a dial indicator set on the retainer on a valve at it's fully open position crank the rocker nut down till you reach the minimum space between your spring coils. Record this amount.