Read the turbo database on
Donovan's Dodge Garage Then read it again.
20+ PSI on what you have:
Assumption: You have a '87 or newer blowthrough setup with stock IC.
1.) Walbro 255 lph fuel pump
2.) Adjustable Fuel Pressure Regulator (not 100% necessary, but it helps)
3.) +40 fuel injectors
4.) 3-bar MAP sensor
5.) Computer calibrated for 3-bar MAP and +40's
6.)
A good way to monitor air/fuel A/F gauge + EGT or wideband
7.) Free flowing exhaust
I have an '86 shortblock (light weight rods, high mileage) with a slightly ported 782 head, 2-piece intake, the above modifications, stock T2 turbo, stock IC and I run 20 psi regularly. I've had it up to 25 psi, but above 20 there isn't much advantage with the stock turbo and IC. Now, this doesn't promise that you won't destroy things. I have burnt pistons at only 14 psi before. It's all about knowing what to watch for and staying away from detonation.