Where does LT1 Procharge belt start slipping?

[HighMileage]

Hi guys, A little background. I have my 5th C4, a 96CE. I have an 89 that I keep under the cover factory fresh. Put 216K on an 86. Put 190K on a 90. Put 165K on a 92. Have built or rebuilt literally everything on a C4 from Lingenfelter engine, 700R4, rear end, interiror, you name it, been there, fixed it.... Was looking to go over to the dark side and get a C5, never really cared for the body style and fat ass. Will own a numer of C6's someday. Got the 96 with a procharger, forged bottom, done professionally. Looks like its pushing about 7 pounds boost. It ramps smoothly to boost, does not jump around. No belt dust is visible on supercharger. Everything seems solid. Stock 7'' balancer and 3.6' blower pulley. Couple of questions: 1. Where do these things start slipping? I am setup to reduce pulleys, maybe upgrade to a larger balancer to increase boost, but I don't want to upset the system. It appears to be working. Is there a blower pulley size that problems will start happening at? 2. My throttle body is stock. I think they flow only 700CFM and that is with an airfoil. Is it worth it to upgrade to a 52mm? I think those flow 900CFM. I dont want to pull manifold if I dont have to for a 58 (would have to port it) but will if it would make a diff. Seems a 52 for 15min of work would be the way to go. 3. Exhaust has been done. Do you guys believe the ATI claim of up to 60% increase? That would put the car at 480 to the crank. Anyone have a RWHP figure for a stock headed LT1? Thanks guys looking forward to contributing here.