I have smoke the ends of some high dollar($23.00 each )pushrods because the pushrods where rubbing on the block preventing oil from getting between the rocker adjuster end and the pushrod cup It sounds like you have s set of Indy cylinder heads, what version and what ratio where the old rockers and what ratio are the new Harland Sharps? How many threads on the adjsusters are showing under the rocker arms? Make sure the pushrods are moving easily with the motor warmed with both valves closed, if this is a solid roller or solid flat lifter camshaft If hydraulic make sure they will move(spin) easily at zero lash I have one motor with Indy SR heads that uses T&D single shaft rockers and another motor with Indy 440-1 heads with single shaft Harland Sharp rockers, I had to grind on both heads to get pushrod clearances set up so they would live The quality of the pushrods makes a difference also, Manton Stage 3 and 5 are the best ones out there for high performance use I sell both Smith Bros and Mantons, I use Mantons in my motors