Checking for Pushrod length
I was re-reading the posts, and what do you mean by seating the adjuster nuts? I know you want to leave a few threads for correct oiling but doesn't the lock nut just keep it in place? Or is there a reason for it to be tightened down with the adjuster nut as well?
The rockers oil best with about one turn out from the seated position (more than two turns out can cover up the oiling hole inside the thread). One turn out is known as the "initial position". The "seated position" is with the adjuster nut fully recessed, or turned all the way in - in other words, loosen the lock nut, and wind the adjuster nut anti-clockwise as far as it will go so that it is "seated" and there are few or no adjuster threads showing below.
Then measure your pushrods like this with no preload.
With the correct length pushrod, all the adjuster nuts should then sit about 1/2 to 1 1/2 turns out from the seated position - or 1/2 turn in or out from the "initial position" (which - remember - is one full turn out) - after you have added 1/2 turn of preload. This ensures correct oiling.
It also ensures correct geometry: the further out (more threads showing) the adjuster nut is, the more lift you lose at the valve, as this will slightly exacerbate the 59-degree angle between the lifter and pushrod on LA (and Magnum) engines.
If you can find a set of instructions for your rockers, then have a look - all that I have explained should be in there.
And really? Didn't know that, I always thought that stud systems were what people preferred. All I know is they are the biggest pain to put together when you have to take the middle rocker out for whatever reason :P
Have a look at the best Jesel or T&D rocker systems for Chevs and Fords - they are all shaft systems. Shafts are inherently stronger and more stable than studs. The downside is, you can't use cheap Chev-style stud rockers. Which is no great loss, IMO.
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