What about 25 ft/lbs.....I have a trq wrench that is like 20years old so it probly off alttle.

 

like I said, worn cam lobes can result from overtightening

 

25 will be fine. Its not going to change the distance of the rocker to the lifter...it will however be on the high side of the recomended Tq for that size bolt. If two mating pieces are butted against each other at 22 ft/lbs....going higher in this case will not make them any closer...only stretch the bolt or strip the threads. But 25 aint a big deal. I hand tighten mine half the time....of course my elbow is well calibrated though.

These rocker are non adjustable. Going 15 ft/lbs ,20 ft/lbs, or even 30 ft/lbs will not change the distance in this case with an LS1 setup. The differences in Tq are only relevant to the actual fastening.

The only way to change the distance would be to:
mill the heads
change PR length
change lifter body length (aftermarket lifters)
shim rockers
use different rockers with diff geometry
different thickness head gaskets
use adjustable rockers, either stud mount or shaft mount with adjustment nuts
mill the block deck

Again...you should be fine. if you wanted to check preload like the link sais...go right ahead....but what you would be checking is the factory setting...since no dimensions have changed.