Let me answer some of these questions....
1. I installed used LS6 valve springs (90# seat pressure w/valve closed) when I did the cam. They were supposedly low mileage (under 40k IIRC), so they would still only have 60k-70k miles on them.
2. Cam specs are as follows:
Lobe Center Sep 110.8*
Valve Overlap -11.9*
Valve Open -5.9*
Lobe Center 110.1*
Max Cam Lift .30622"
Valve Open 36*
Lobe Center 111.5*
Valve Close -5.9*
Max Cam Lift .30642"
These specs are very similar to a ZZP GT1, and with my LS6 springs there should be no float. Also, when I said we retarded the cam 6 degrees, I meant we changed it 6 degrees from the previous timing. It had been 6 degrees advanced, so all we did was return it to stock timing.
Dyno chart for the previous cam timing (6 degrees of advance):
Valve float was never a problem when doing this dyno run, so I don't think I would be experiencing float now.
3. As far as fuel is concerned, I haven't checked fuel pressure in about a year. I was getting a little KR on the top end after returning the cam timing to stock, but Thomas added a little fuel with HP Tuners and the KR went away. As of our last tuning session I have no KR. My fuel sender is a little wonky (fuel gauge is completely inaccurate), so maybe the pump is having problems too? I also have 25# injectors, which are a few pounds higher flow than stock L36.
4. I am intrigued by the theory that my tranny pump might not be keeping up. Does a gear ratio change affect pump RPM, or is the gearing independent?
5. The possibility of not enough air flow will soon be addressed by the installation of a stock L67 throttle body that has been modified by Doug to adapt to the L36 UIM. I will also be doing some wideband O2 tuning with Thomas (PDXGTP) to make extra sure the A/F ratio is right.
Sorry for the long post. If there is anything else I can clear up, please ask. I'm willing to explore many different possibilities at this point. The car doesn't necessarily feel slow... I think "unimpressive" might be a better term to describe the upper RPM range. This thing should be set up to accentuate the high RPMs, but instead it seems fairly lackluster. I might be running the 1/4 mile in current form, so I may have some numbers to relay to you all on the 13th. I just want to get this thing figured out and running in top form.