360 j head valve stem diameter?

You really should get the right length push rods. Tipping the rocker back or forward more than it's designed angle is not good. Plus if you are running a hydraulic cam it would be very easy for a lash cap to be kicked out. If you had a lifter bleed down while it was sitting then when you started the motor before the oil in the lifter could take up the clearance the lash cap could fall out. Or worse get jammed sidways in the retainer or rocker. Lash caps should only be used with a mechanical cam.

Chuck