I've used plastigage on stock rods for a while and always work. I'm rebuilding my LS/VTEC with FJ Dist. forged rods and for nothing I can remove the cap without squeeze the plastigage.

I'm holding the cap back the most I can while gently tap on the bolts of the rod to remove the cap but always I damage it. Any trick or advise?

 

put the plastigage between the top half of the rod and the crank. when loosening, unthread the rod bolts about halfway then with a stocket and extension on the head of the bolt, lightly tap it with a rubber mallot until it frees itself off the dowels. that way you are pushing the plastigage away from the crank instead of of toward it.

also when tightening and loosing try and have your wrench perpendicular to the length of the crank to reduce the chance it rotates over

 

Very Thank you, Sir.