72 duster 360 NA to 390 Turbo

It may build a pound or 2 but this turbo is a little lazy and the brakes won’t hold and it either starts spinning or pushed the front tires. I’m sure if I pumped the brakes up and pushed the accelerator more then I have I can maybe get 5psi. I may try to test that next time. Yes cam is degreed and timing is rather low, it’s what I set it to when I installed the engine.
Turbo lights off immediately on street tires and spins forever or until I put it in a ditch!
2 step should help some of my issues. All my LS buddies say it’s definitely needed. If not, then we learned something.

I really need to spend a week dialing this combo in on the dyno which I hope is soon.