I have a 92 Spirit R/T, basically stock, only known modifications are 2.5" exhaust. The boost will spike until it hits overboost shutdown. It does it with factory boost control and with a g valve. If I set the valve for the lowest setting (~8psi roughly) it will spool slower but still creep until it hits OBSD. The vacuum hoses and everything appear fine, and the wastegate isn't stuck, it seems fine. I'd go with a 3 bar cal if I could find a 92 TIII core, but no luck. Any help is appreciated.