Oh no. I just read your other post about Kendall replacing a pump and voiding your warranty. Did you authorize them to do the $600 job? Or did they just do and give you the bill. The law covers you if their repair didn't work. Their mis-diagnosis is their fault, not yours. Get your money and old pump back!
Oh, and the the turbo dragging deal... are you sure your BD exhaust brake isn't sticking partially closed??
A 'turbo dragging' answer seems odd to me, but if it is DO NOT pay $1000+ dollars and core to Cummins to replace a stock turbo, especially when you can get a brand-new hi-perf HX35 from Piers for about $600. If you need help installing I can help.
-Mike