sorry to revive this thread, but i know what you are saying. the only thing is, there is not a "tune" for a p-pumped cummins. and with a couple grand you can build a bulletproof auto trans, and a good clutch and your dodge stick shift will last forever. i know, because i have several friends with both auto's and stick shifts. and the reason why most believe the cummins engines are superior to the others, is simplicity. a straight 6 will always last longer than a v-style engine. that is why they put them in semi's. and head bolts dont necissarily mean much. you have six cylinders with one head on top of them, versus 4. with a set of head studs, you can run as much boost as you want on almost any diesel engine. the problem with powerstroke's is the heui system that they utilize. it can only fuel so much, and it does a great job inside its limits.
The mechanical p-pump is what many switch too in performance applications, if they dont already have it. that is why many 24v cummins owners switch from electronic injection to the p-pump, along with a few powerstroke owners who use their machines only for pulling and such and want the most power they can get. hell, i wouldnt be surprised if there are p-pumped duramax's out there.
This coming from a cummins owner, who was about to buy a powerstroke a few days before
oh, and btw, my trans is about toast. but it lasted 215k miles of abuse. and i know it was abused because i bought it with a broken front axle and a weight rack hanging off the front end.