For the intercooler I'm running stock ZL1 cooler and it is sealed, I didn't tee my cooler into anything. I'm running it identical to the stock ZL1 with coolant antifreeze mix. The car survived the -17 degree day during the deep-freeze last month and no issues. Waiting for summer to see if it actually gets hot or not. No real pressure build up. I check it today in 75+ degree weather and in town commuting, not an issue yet.
How are you tuning it? Or did you get it with a tune? I've been dialing this thing in for weeks with my hptuners software and I'm still not done. I am stuck with the fact that I have an automatic and if I am cruising it gets into sixth gear then when I get on it it doesn't drop into PE mode fast enough, starts to get too lean and will have some spark retard. I'd I roll into it or manual shift it goes into it then I get something pig rich in the 10:1 range.
I started over again tuning the VVe table and now and pretty confident, but still dialing in the LS7 maf curve.
You said you got an updated tune, one you paid for or did yourself? I progressed along on my tuning for a while doing VVE and timing changes and it ran very smooth at normal and part throttle, but could not get it to go into PE mode quick enough...goes lean first then into enrichment then goes pig rich and bogs down a bit. As long as I drive it part throttle it is great and 50% throttle it is fantastic. But cruising along constant speed then getting into the throttle causes the initial lean tip-in as well as transmission downshift and then it had issues. Slow and smooth roll into the throttle then to full throttle and it is fine minus being too rich and bogging down part.
Which is pretty much where I left it as I'm away on business for quite a while and I parked it till I can get back to it.