I've read on here about useing aftermarket roller bearings in the stock rockers, can someone explain more about this mod, what bearings to use?

Thanks.

 

The best upgrade I know of for stock rocker arms is to press the needle bearings out and have a bushing pressed in. The stock rocker arm needle bearings can fail when heavy valve springs are used. Richard @ WCCH has info on the bushing mod.

 

I believe that Harland Sharp does this mod. It's covered pretty well over on ls1tech.