noisy valve train
We recently built up a 289 with an Eagle-brand 347 stroker kit and Edelbrock Power Package flat-tappet cam/aluminum heads/intake kit. Roller rockers are utilized as well.
Engine runs great, but after a couple of hundred miles the valve train now becomes noisy after the engine is up to temperature.
Went back and check all component specs, including pushrod length. Also checked oil pressure - 35 psi @ 1000 rpm. Have adjusted preload on lifters several times now. Summit, Edelbrock, and local shop's recommendation are vary slightly, but have tried anywhere from 1/4 turn to 1 full turn most recently. Still noisy when hot.
Any suggestions? One shop suggested I'm getting a lot of expansion from the aluminum head and need to go with even more preload, but that does not match any manufacturer's specs. Another shop said the lifters may be bad. Any information would be greatly appreciated, as I am out of ideas.