I'm putting together a mild street engine... 383 block with 440 crank, Stealth heads, block deck squared to crank centerline so I can build a quench engine. Camshaft is Comp CL21-223-4, which is fairly close to a stock HP camshaft.

I had some almost new MP stamped rockers and shafts (repackaged stockers, I believe) that I thought I'd use since I had them, and since I figured this engine didn't need an adjustable valve train. I'm beginning to think I was wrong.

The camshaft instructions said valve lifter preload should be .030" - .040". I checked #1 exhaust and it was .032". Perfect. With the same pushrod in #7 exhaust, I had .085". I stopped at that point to try to figure out what's going on.

I have not swapped rocker arms from position to position to see if that's where the difference is, but it is probably what I should do next, to at least find out if I need some different rockers. I also wonder how precise this setting was on new engines back in the day. In theory, since my deck has been squared, I should be better off than if I hadn't.

What gives? Am I fighting a losing battle? Is it time to cave and buy some adjustable rockers? Would it be acceptable to file/grind them at the bottom, where they contact the shaft, to get the preload right, or are the hardened/coated there?

Thanks!