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Author Topic: swapping 1988 454 400 into 2000 3500 hd diesel  (Read 582 times)


  • Single Axle Driver
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swapping 1988 454 400 into 2000 3500 hd diesel
« on: May 26, 2018, 12:25:35 PM »
I am swapping 1988 454 400 into 2000 3500 hd diesel. the diesel motor is gone rolling chassis truck i bought. I dont care about mpg. going to use the truck maybe 3000 miles a year pulling grain wagons etc.

the 1988 doner truck had a dash fire 88k miles motor has 12k. computer harness melted in dash fire. picture 100% mint 1988 c3500 with dash wiring and hvac case missing seats carpet etc mint.

I will have to run a carb and msd box. will the motor mounts work from the 1988 in the 2000? I will have to fab a drive shaft. flush the tank and run a carb fuel pump. will the speedo work or can i make it work?

will the radiator etc front dress all work?

I do have a 1995 350 c3500 parts truck has wring but its high pressure tbi vs 1988 454 had low pressure
i also have a 1994 6.5l diesel cab complete

i wanted to salvage the 1988 so clean but cannot locate complete dash, hvac,harness and ecm and engine harness at reasonable price
The hd will get more use if anyone needs a rust free 8ft bed or extended cab they are rust free and will be for sale


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Re: swapping 1988 454 400 into 2000 3500 hd diesel
« Reply #1 on: May 26, 2018, 01:24:30 PM »
I put a 94 3/4 ton cab on a 1995 3500HD former diesel chassis. Motor bolted right up, I used the NV4500 tranny from the 95 diesel so I didn't have any driveshaft concerns.  The NV4500 also has the parking brake drum tail shaft...not sure how your THM400 is set up.

Installed a 350 engine with tune port injection and wired in a TPI (730) ecm.

Repining the 94 gas/TBI cab to accept the 730 ecm wasn't hard.   If your 88 driveline is TBI it's really not too hard to convert the harness into a 4 wire standard alone harness and run the 88 ecm.

I used the 95 diesel chassis lift pump fuel line connection for my gas fuel filer (bolted right in). I bought a gas sending unit for the diesel tank and installed a TPI fuel pump....the tank worked but there is no gas splash pan in the diesel tank. If you run TBI you need the lower pressure TBI internal pump.

One important item was that the  95 diesel chassis had both the fuel supply line (3/8) and a non functioning return line (5/16). It was non functioning because there was a rubber block in the return line line junction near the lift pump area.

GM Guy

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Re: swapping 1988 454 400 into 2000 3500 hd diesel
« Reply #2 on: June 11, 2018, 08:47:25 PM »
The accessories will not match, but the 94 6.5L will bolt up. you will need to find a blown up 96-2000 to strip for accessories.



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