Ok, thanks.

 

I used PAC , I think they are a good spring although I think GMs new OEM springs are just fine as well.

I used a cylinder leakdown tester to apply air pressure to the cylinders, was very easy to use and I got a leakdown reading for each cylinder now (all were about 1% which is good).

I bought this one and replaced the % leakdown gauge on the right with a cheap PSI gauge since the % one was worthless.

http://www.harborfreight.com/cylinde...ter-94190.html

Another key note - I applied about 100 PSI at TDC of each cylinder. You must be right at TDC or else the air will turn the engine over. To find TDC I put a breaker bar and socket on the big pulley nut for the alternator. The crank nut would be better but I couldn't get on it. Anyway I had my buddy turn the engine slowly while threaded the cylinder side of the leakdown tester into the plug socket - then I got close to the end of the air line and held my finger over the hole, so that as my buddy turned the engine over I could feel either pressure or vacuum developing - pressure meant we were on the up stroke. I'd keep bleeding off the pressure with my finger until no more pressure was coming, this was typically TDC - if he cranked too far you will start to feel vacuum, so spin it all the way around again (can't go backwards or the belt tensioner lifts up and the belt slips on the pulleys).
Its a bit of a PITA at first, but once we got the hang of it I could find TDC in about 30 seconds per cylinder. We did both our cars like this. I liked doing it this way because not only do we have air pressure holding the valves up, the cylinders are at TDC as well just incase we lose pressure or bumped a valve and broke the air seal.

 

I was working on replacing my original springs, plugs and wires today. Bought the LS2 replacement springs for gmpartshouse.com (blue springs). I made my own air tool up from an old plug cut it in half, welded it to an air hose fitting, and added a 2" steel tube in between to lenthen it enough to be able to hook the air hose to. That part worked great but I tried to use a cheap autozone valve spring tool, uh yeah, that was not happening. It may work for replacing one broken spring but there was no way I was going to do all 16 with it, that thing was hokey ($19.99). Anway, just ordered the trickflow tool from Summit ($79 shipped) that looks like a waaay better method. Looks like I'll be finishing the job up next Saturday. Also, I now see why everyone seems to replace their plug wires while changing springs or plugs. Mine were stock and were a pita to get off, as soon as I ruined the first one it made the rest a lot easier to get off, lol

 

I decided on the PAC 1518s on my stock cam because they have the same specs as the 1218s, except they are miro bead blasted and nitrited for increased lift and mainly for increased reliability <--- key reason. I'm only doing this job once, so went with the best available.