How hard is it to do a 8.1 to 6.6 swap in a 2003 chevy 2500hd. does anyone have pictures? or infromation on this swap? we have a seized 8.1 motor from flood damage and looking for a donor 6.6 (probly totaled) to do complete swap motor and computer but tranny if needed. but i can keep wiring harrness cant i? please help with any infromation!

thanks
Matt

How hard is it to do a 8.1 to 6.6 swap in a 2003 chevy 2500hd. does anyone have pictures? or infromation on this swap? we have a seized 8.1 motor from flood damage and looking for a donor 6.6 (probly totaled) to do complete swap motor and computer but tranny if needed. but i can keep wiring harrness cant i? please help with any infromation!

thanks
Matt

The wiring harnesses are not the same, so I don't think it would work.

shouldn't be to hard, especially considering the suspension is the same. you won't have to do a body lift.

I'd use a LLY or newer to get away from the injector issues. Complete engine compartment wiring will be needed. Dunno about the trans, probably best if the donor trans and it's controller was used too.

jb

Apparently no one here pays attention to other posts, there are more than one threads on swaps, most include the 6.0 but the 8.1 is even easier because it is already a HD and the fuel pedal is already electric. Look up Duramax Yukon and Escalade Swap to find current threads on this type of swap. It is almost a direct drop in, and the wiring is very similar. With the 8.1 you should not have to do any wiring changes. If you have questions feel free to ask between myself, theTDIguy and TractorNate this one is a slam dunk. Oh yea you need a Duramax that is 2003 or newer.

This should be easy if you ask me . Goes right in and just need DMAX harness and fuel supply and all the intercooler parts .

Will bolt right in . Same motor mounts and truck already has Allison .

I have a 8.1 2003 that I would like to do the dmax swap to also .

It is big and the one in my avatar .

Don't forget about the Duramax/Allison Badge for both doors.

Apparently no one here pays attention to other posts, there are more than one threads on swaps, most include the 6.0 but the 8.1 is even easier because it is already a HD and the fuel pedal is already electric. Look up Duramax Yukon and Escalade Swap to find current threads on this type of swap. It is almost a direct drop in, and the wiring is very similar. With the 8.1 you should not have to do any wiring changes. If you have questions feel free to ask between myself, theTDIguy and TractorNate this one is a slam dunk. Oh yea you need a Duramax that is 2003 or newer.

That is what I was thinking about was older than an 03. Then it woudn't work.:o:

so if i pluck the 8.1 out of my 2003 chevy 2500 hd and i buy (probly totaled/wrecked/rolled) 2003 dmax donnor truck i will just need motor, computer and harness on motor will connect to harness coming out of the computer correct? drop in put intercooler in(does it go with current core support or will i have to chenge it) and then add 1 wire to instrument cluster for wait to start light? done deal right? oh yeah if i have 3 inch pipe not will manifolds bolt right up?

In a very simplified example that is exactly what happens. The computer you talk about is attached to the engine. I am not sure about the tranny, I have always delt with the drive train as a whole and have never mixed and matched. You will need to research the radiator/intercooler interface I am not sure if the radiators are the same or not, on the 6.0 it is a different radiator but as far as I could tell the core support was identical. Again it would be in your best interest to research it yourself before starting. As for the guage cluster you just have to add the wire for Wait to Start light. The exhaust is different, diesel has a down pipe from the turbo gas has exhaust manifolds to connect to. I am pretty sure the mufflers and cats are different also.
Fix up the fuel system, which is done easiest with body removed. Do a computer relearn process and it should fire right up.
You might want to check the tranny mount loctions between a 8.1 and a duramax and then the drive line lengths. All of the parts you will need can come from a totaled/wrecked truck.

Don't forget about the Duramax/Allison Badge for both doors.

thats the main thing

finding the wrecked truck is a chore to find . found a few in the past , but they wanted a fortune .

well i buy from serveral salvage auctions copart, qcsa, iaai, metro and local stuff so i can find stuff yeah sometime it can be hard to find but i can get a rollover wrecked 03-05 dmax 1800-4000 depends on how messed up. i am gonna try any buy one tommorow accually!