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GMC c7500 with 3126 swap to a m11?

Bg1004

New Member
Joined
Jun 4, 2024
Messages
3
Location
Elgin IL
Hello guys so I’ve been having this idea for a while. I have two tow trucks one is a 2000 gmc c7500 with a 3126 and a 6 speed manual perfect engine it’s wonder it’s been nothing but kind to me but it’s really really really under powered for the truck it’s in. The truck it’s self has a 20 ton wreaker system and of of the strongest suspensions I’ve ever seen in my life but when I get pulling it’s really bad on power even its own weight is an issue. So I have this other tow truck that’s a 1989 international with a m11 and a 8 speed 8LL. The truck was an absolute animal on the road quick and fast but unfortunately it has the opposite problem wayyyyyy to much engine wayy to big of a system (30 ton) for a measly air ride single axel. I was wondering if this would be possible since I’m already transferring the system to a t800 tandem. And the trucks is rusted out and in terrible condition. Any help or ideas would be appreciated and may the lord return it to you. Thank you guys.
 

crane operator

Senior Member
Joined
Mar 27, 2009
Messages
10,145
Location
sw missouri
Personally, I would rather remount the bed on a truck you want, vs swapping engine and wiring harness. But I prefer fab to electrical.

The m11 might be a tight fit in the 7500, I don't think they came with a m11. Plus that transmission is going to be bigger and longer, so driveline work too.

I've repowered a couple cranes, and they were mechanical injection pumps, so not much electrical, but they were still a lot of work. Every time you move or mount one thing, something else is in the way.
 

Old Doug

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Oct 16, 2013
Messages
5,573
Location
Mo
I will give you my 2 cents. I have done several engine swaps on cars,pickups trucks and equipment . I have built 2 Chevy powered fords. I have a truck like yours with a gas engine my thing is i want more gears. That m11 would be a lot of engine do you have the time, are you good at seeing a prodject through ? What can you buy another truck for?
 

CM1995

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Jan 21, 2007
Messages
15,952
Location
Alabama
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Running what I brung and taking what I win
Welcome to the Forums BG! Glad to have you.

Not much of a truck guy but I too would suggest finding another truck to mount the wrecker body to.
 

56wrench

Senior Member
Joined
Dec 4, 2016
Messages
2,492
Location
alberta
With the bigger engine, the radiator could be an issue too. It sounds good in theory but I personally wouldn’t do the swap
 

Bg1004

New Member
Joined
Jun 4, 2024
Messages
3
Location
Elgin IL
Sorry I forgot to add why I wanted to do the swap. But either way thank you got all the replies. The reason why is this platform is just built so well. The c7500 is ver similar to the m2 and the fl60 the only difference is that I can see absolutely everything out of this truck I don’t need spotters and I can blindside in one go. It’s truck such a simple truck to drive. So I really want to keep this platforms I’ve had all kinds of trucks in my fleet form Peter builts alll the way down to Hinos and the c7500 and the m2 are truly the easiest trucks to drive. I get that kenworths and pertebuilts at the staple of the American trucks the Turing radius on those trucks are poor along with viability. And why the m11? Because it’s actually the only engine I have on hand. Are there any other suggestions for what engine to put in this c7500 to get a better hp rating?
 

Truck Shop

Senior Member
Joined
Dec 7, 2015
Messages
25,150
Location
WWW.
ny other suggestions for what engine to put in this c7500 to get a better hp ratin
From my years of experience,-----doing a repower of this type can be tough. If it was a PacCar or
Freightliner product it would be easier, repowering a Ford, Chevy or other can be a real headache
from the stand point of sourcing parts. Even repowering a International can be a real head scratcher.
Your correct about turning radius--Freightliner just about has the others beat in that department.
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The trouble with all projects like this is the unforeseen issues, really it's project for a experienced
truck fabrication shop, and that option is very expensive and mostly out of the question. I've built
allot of trucks through the years and as each year passes it gets to be a less manageable idea.
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Like the others noted above---for all the time/money invested--you would be better off to find
another chassis spec'ed the way you need it and move the 30 ton unit to it.
 
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