5.9L in K2500
I did this exact conversion in my '93.
First and foremost, you absolutely must put in a 2" cab and bed lift kit . This will help the clearance above the transmission. Without it, you also cannot close the hood.
I used a GM flywheel, with a LUK 12" clutch and PP. Change the IP shaft to Dodge will work too. Probably less trouble.
The rear drive shaft must be shortened 2" and the front 4WD shaft must be lengthened 2".
Each crossmember must be removed, new holes drilled and moved back 2".
For my ac Pump, the lower front AC pump mount had to be cut 1" and shorter bolt used, it will hit the right rail. Found a Dodge AC hose, and facricated a mod hose. Newer 97 Chevy pickup AC hoses are a near bolt on with the Nippon Denso AC pump to a GM body tho+.
I used the Nippon Denso "DODGE" alternator, put a "spider" internal regulator in it (rebuild shop had it, won't give out PN) and added a wire from the windings for the tachometer, then plugged that into the GM alternator hook-up, and provided a field. perfect tach and charging.
I used my electric fuel pump, used the GM oil pressure sending unit, and bought an adapter cable from GM and plugged it in. Perfect oil pressure and smoothe power. Smoother than just the Dodge lift pump. Quietened it at idle and made for romp acceleration.
The shift hole has to be cut 2" at rear, and the shifter heated and bent. Not the handle, the shifter in the transmission. Remove it, bend and fit. Took me 4 bend and tests before I got it right. Otherwise the shifter lays on the seat.
Getting the engine to drop between the rails was a 2 hour process. You only have about a 1/4" and the engine must be perfectly square. If you do not have a tilt sling, you're in for a @#$%^&!! of a time.
Set the engine to TDC and remove the harmonic balancer, remove the speed senser, and if automatic, the control for the transmission at the pump. They'll get damaged. The engine will hit the balancer at radiator support.
Tie a string to the oil pressure sender wires, cause this big Cummins will hide it and my hands won't fit back there to find it.
I used a K & N filter kit for a Dodge, cut 2" off the shield bracket and trimmed the tube. Looks like OEM.
For powersteering, I used a Tee fitting and routed the third return line into the 2d. Excellent PS and no backpressure. Brakes work fine too.
For Intercooler, Good Luck. I'm still using the GM intercooler with fabricated pipe. While it runs cool, it is the only dead give away that my truck has a modification, till it runs, then you know, if you know engine sounds. I have 2 Dodge intercoolers, and without serious booger-rigging, they won't fit.
For fan, I used a 18" plastic fan, a screw on adapter, and it runs all the time. With this engine, how'd you hear it?
Fabricated a bracket, using the GM accelerator cable, and cruise works perfect as does throttle.
I had a 300 HP 6. 5 low compression, so I gave up speed, but low end torque is a little better, and overall towing a lot better.
I have towed more than GVWR multipled by 2, and go gets the green light, Whoa gets a caution light. Same loads towed with the Low Compression 6. 5, but low end is stronger.
Summary. Nearly 50K, about the same mileage that most honest people say they get with a Cummins. Still using 4:10 gears, so max speed is 86 MPH, which is OK. No real need for a GSK kit yet.
I have a bed tank, so I fill up about every 1000 miles, and I get 16 at 75-80 freeway speeds, and 18. 5 drinving sensibly. Almost all the miles are towing something, and my low is 13, my high is same as empty. Average towing is 14. 5 -15. 5.
I have not had any indication that my little 12" clutch is not enough to do the job, but my Cummins is only running about 300 HP, which is plenty.
Despite the smaller intercooler, my engine temps never get over 150, and no overheating, even with SERIOUS loads.
Would I do this conversion again. Yes, but it would take less time.
Wayne
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