I have a totaled, but complete 98 K2500 with the NV4500. Has a goodwrench crate from about 70K ago. Still starts and runs great. Was t-boned in the drivers door at speed. Frame and cab are destroyed. It was an impressive strong runner directly before the accident.
I also have a complete and running 93 Yukon. 350TBI ofcourse with the NV3500 bone stock. Decent rig but with 350K on it, it likes to burn oil. You'd never notice if you didn't check the mirrors.
I had thoughts of swapping the 5.7 vortec and tranny into the Yukon. There is a very skilled LS / Vortec wrench in town that loves to mod and tune. I mentioned this to him and he gritted his teeth. He is not a fan of the 400s and said this would take alot more than I'm thinking.
I assumed just the full wiring harness, computer and a fuel pump...basically.
I did some digging online and get very limited info on a direct swap. This tells me he's correct and I've always trusted his opinion. He said he might buy the truck complete, yank the engine and sell it, keep the tranny and crush the rest.
I'd like a second, third or fourth opinion from those that know telling me to just stop wasting time looking into this. Just rebuild the TBI in the Yukon or try and find a decent TBI to swap in. Or, since the Yukon is just a mountain camper, forget about it and enjoy the mosquito repellant option.
Thanks.
Greetings yeobee,
The ability to successfully pull off an engine swap basically boils down to how complete a donor vehicle do you have to work with?
In other words, the Tail that wags the project Dog is the endless chase for the small showstopper bits that nearly always
cause swaps like this to drag out far in excess of what you forecast going into it? Or you are trying to parts bin engineer
a cross-generation combo that never came off the assembly before? And halfway into the project you discover why this
hasn't been done before? Note: A lot of these concerns are trivial when you are working with a couple of 2-3 year old vehicles
thanks to fully populated treasure yards...but when you are dealing with 20-30 year old vehicles, sourcing these showstopper bits
can be so much harder. (Especially when the vehicle you are working on is enjoying a wave of popularity, like our GMT400s
are in the middle of.)
From my perspective, this is how I view potential remotor swaps, in order from the
hardest to pull off to the
easiest:
* Only have the bare engine from a different generation SBC or LS family > existing vehicle
* As above, but the original engine has all of the accessories still on the front. (!)
* Donor vehicle bought for all the necessary bits, not running, unknown service history. (Online purchase, auction purchase, etc)
* As above, but was running, you heard it, bought from PO, and they could give you a least a verbal history of the machine.
* Using a donor truck where you personally
know the history, the lack of SES DTCs, how it drove, wiring harness behavior, maintenance history, etc.
In English, what you have on hand is a best possible scenario for a swap project. And if you have been on this forum for awhile
you realize that you can give yourself a secret weapon in the fact that there's a cache of Factory Service Manuals in here that will
prove invaluable in minimizing the guessage factor in making this swap. (Get both the '93 & '98 searchable free manuals over
here.)
For what it's worth I'm sharing this from the perspective of having gotten involved in more than my fair share of swaps.
Some I instigated, and some I was asked to join in and help troubleshoot an engine swap that wasn't playing pretty
after the fact. In summary, it's never the fully factory engineered areas that cause heartburn & sadness. It's where *we* are
doing the shade tree engineering trying to merge 2 different generations together. So, using the '93 & '98 books and figuring out
exactly where the physical and electrical merging is going to occur will give you a lot of heads-up as to where the work-in-progress tears
may potentially fall. :0)
****
And just so I don't come across as a engine swap Pollyanna, here's a cautionary tale near the beginning of the hobby for yours
truly: (
make assumptions = swap twice)
And if you decide to do this swap,
don't throw *anything* away. At least wait until once the dust settles after the swap and
the new combo has proven itself reliable. (Single biggest mistake people make.) And take more photos that you ever thought
necessary of both engine bays prior to you putting a wrench to it. You might take a photo focusing on one thing, but the wiring
harness colors going to a sensor in the background is the answer that you ended up needing. If you don't have a small engraver,
think about getting one. They're cheap, and sometimes just being able to match up 2 arrows that you did in seconds before you
took it apart will save you hours of research when it's going all back together days/weeks later.
Lastly, if you do all the above & still get stuck, there's plenty of remote talent in here who can help you get the '98 upgrade to
get back to work in your '93.
Hopefully the above puts all this into a proper perspective. Assume nothing, and you will avoid eating as much humble pie as some
of us have while trying to take 2 good things (with dovetailing strengths & weaknesses) and achieving some sort of mechanical
synergy with the resulting swap patient.
Just my 2¢ worth, based upon my own personal misadventures...
