THAT'S ONE BEAUTIFUL & AWESOME LOOKING MACHINE
Great Job with the build, it must have been awesome to finally drive it for the first time, CONGRATS
It sounds Great , looks Insane, and I'm sure every single person that saw it was thumbs up, it doesn't get much better than that
To answer your questions no I haven't experienced any detonation with the 351w but I am aware of how bad it is and fast it can take your motor out.
The Lightning & Sierra are the 6th & 7th Supercharged Vehicles I've owned so I have a lot of experience with them. The Boost Gauge is the next thing in line to fix on the 351w so I actually dont know the exact Boost "yet", I'm working on straightening out the Sound System and Gauges now. I've been driving it a lot lately including an out of State Trip and it runs great and trouble free in all driving scenario's, I estimate the Boost to be @8
AS for the Sierra here's a couple of pic's for you
I just removed the Dual Air Cleaner and installed the Mr Roadster Scoop a week or so ago but after I did I realized I may not have enough air cleaner to feed this monster so I may switch to a BDS Scoop like you have at a later time.