86 GMC Suburban 2500 Duramax swap

Bandit_T/A · February 16, 2019

So I bought this Ambulance with a Duramax the other day for less than half of what just a motor would have cost. 2010 Chevy Express 3500 ambulance. I own a 86' GMC Suburban C2500 that is in pretty nice shape for a old squarebody with a 350/400 combo. The ambulance was layed over on it's side and stamped as a salvage title. From what little driving I have done with it the motor and trans are great. The suburban drives good but I overheated the motor last year on the way home from camping and I had replaced the heads which were both cracked but I had been thinking about a cummins swap when this Duramax popped up and with everything there to make a full swap I figured whats the worst that could happen. I done some research on the job and studied a tread that was done that's similar to mine with a van motor and wiring harness being fitted into a dually truck. I would like to retain the cruise, tow/haul, & manual shift if at all possible.

silveradosid · February 17, 2019

sounds like an awesome summer project since you have the wiring harness most of that will be easy. if you can switch over the steering column the biggest problem you might run into is firewall clearance i believe the newer trucks have a larger tunnel to have room for the exhaust down pipe off the turbo

Bandit_T/A · February 18, 2019

I'm talking to a guy that builds stand alone harnesses. I'm not entirely sure theres enough wire to do what I want on the factory harness. There is quite a difference in engine bay length between the 2.

Edited February 20, 2019 by Bandit_T/A

dmax_ty · February 22, 2019

Speak with Russ at RPM Motorsports. He can help you get the harness(es) squared away.

Aldo, cool project! You may need to beef up the frame. Even the de-rated Duramax you’ll pull out of the van has enough torque to pretzel the stock frame of the ol’ burb.