I'd just build one of the motors you have laying around for the 250's and swap it in when done instead of swapping injectors into a pmr motor...going through the trouble of getting tuning and everything worked out just right only to blow it a week later and have to do it all over again
If you want your stock turbo to last you better drill out the housing and waste gate hole larger or plan for it to blow fast. Buddy is running the same set up and it blew pretty quick. Rebuilt it and now with the modded housing it seems much happier now.
Why?
Dial the tuning in and done.
For example, the "emissions" tune I have for my truck dyno'ed at 240 hp to the rear wheels, just a bit more than a bone stock truck. I can run that thing at WOT straight uphill and baaaaaaaaarly crack over 900* F on the EGT gauge. Can't do that with stock injectors.
My towing tune makes the same power as a full blown race tune, and I can't get EGT's over 1100 degrees with a load behind me. Again, can't do that with stock injectors.
In short, there's nothing wrong with putting larger injectors/nozzles on an otherwise stock truck. Folks need to reverse their thinking in regards to "X" injector is capable of "Y" horsepower, and if you aren't built to handle that amount of power, you'll blow your truck up. That's simply not the case. The tuning can be dialed in to limit the amount of fuel, and what most people will find is that they have a better running truck than before.