whats the proper valve adjustment
for a 1998 500 hp carb motor.

I go one-quarter turn past zero lash. Eveyone, feel free to throw in your preferences.

RS,
I am gonna piggyback on your thread here because you may encounter the situation I had. I set all my rockers at 5/8 past zero. I had 3 (number 1 in/exh and 3 in) that still clattered a bit. I ended up setting these at 1 full turn and they were quite. Anyone have an idea on how much is too much? Crane says 1/2 to 1 turn. That may be fine for automotive but is one turn ok for sustained high RPM? I do plan on going back and setting them to 5/8 or 3/4 and see if the noise returns. Someone mentioned that since the push-rods were used the noise may have just been a fit/wear problem. Since they have run together for awhile it may be ok now.

If you use a stethoscope you will notice that the forward lifters are a touch noisier. With Crane roller rockers with tie bars what you are hearing is the slop in the tie bar. More oil pools at the rear of the lifter galleries if the engine is sitting in the boat. The oil dampens the noise somewhat. The noise is only detectable with the stethoscope and is very slight click, not a tick.