[markjohnson]

I would avoid those Jesel Shaft Rockers pictured above like the plague. When I freshened my last 540, I happened to notice that 8 of them were cracked across just in front of the nose roller pin. Also, you'll discover that there were several added-cost options to them meaning after you spent all that money for shaft rockers, you didn't even get top-of-the-line equipment like you thought you were getting. Best thing you could do is make sure that you have extra-long lower shank rocker studs for strength, keep your existing rockers, lose the stud girdle (I really hate those things), and buy those cheater OPG valve covers that are just a little bit taller than stock ones.