The wear issue behind the cam gear is also caused by high performance oil pumps that "draw" the camshaft rearward as well as the rotational forces of the lifters, the best solution I have ever heard of is to get a Cloyes cam gear thrust washer, or similar, and drill a small (1/64") hole in the block at the oil passage into the face of the thrust surface to help lube the thrust, one word of caution though, don't do it if not planning on a new camshaft because it will cause a different lifter to cam lobe alignment and premature camshaft failure...
The LS6's had 10.5:1 comp. with open chamber heads, closed was 11.25:1 (Tom's memory still works.).
Camshaft condition can be checked with a dial indicater and a degree wheel, but takes forever and a day...the cheat is a good magnifying glass and what you are looking for is porosity in the lobe sufaces, if there is any porosity at all, its almost guaranteed the cam has reached its useful life, its backwoods but has proven itself over the 35+ years experience of my dads machine shop. IMO when it doubt, change it out...
As far as lifter assignment, keep the boxes lifters com in.. you can put the lifters in the box in the order they cam out in and all you have to do is mark the lower part of the box as "front" and keep the lid on it and put in a safe place, if someone bumps the motor while on a stand the lifters could fall and you just bought a camshaft (been there and done that).
Ignition timing...go and buy a cheap OEM knock sensor for a late model (1988-1999) Chevy truck ($20) and install it in the 1/4"NPT water drain hole in the block, buy the Help line repair plug for it too, then run the wire to the dash to a high intensity shift light with a 12V source going to the other lead of the light, the light can be mounted temporary, the knock sensor is a piezio diode and "makes" when a knock is present, causing the light to "flash", its cheesey but cheap, then keep advancing the timing to advanced until it will give an occasional "flash" upon accelleration, then back the timing down 2-3*, your done, don't forget to index the distributor when done incase the dizzy needs to be removed for any number of reasons....
All of this comes from making all of the possible wrong moves over the last 20+ years of playing with big block Chevy's and having to do stuff twice, so take it or leave it.
Good luck.....
GT
