12v swapping 88 k3500 gmt400

Rdeselle93

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Feb 8, 2024
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I have a 88 k3500 dually with a 454 with a 93 chevy nv4500. Truck originally had a 350 tbi and turbo 400. Blown a few motors since then now going the 12 valve route I'm wanting to keep my tranny and transfer case 241c and make it mate to a 96 12 valve. If anyone have any advice; parts; parts list; and how to's itd be greatly appreciated

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I don't have any words or wisdom, but we'd love to see some pics of your truck and the process along the way.
 
Love to see what you do

Just about anything you need to you can find on DCS's website.
Chevy 1973-1988 Straight Axle Trucks. Crew Cab / Suburban through 1991 - Diesel Conversion Specialists

As for advice, double check you triple checked measurements. Confidence is key, second guessing and over thinking isn't a terrible trait when making sure everything is right but do it too much and it really drags things out. Every build is different for every person, no one does one thing the same as another so dont be afraid to do things your way or even explore using so more modern or updated parts. For example super duty radiators have some of the best heat transferring capabilities and are readily available everywhere. Also, my personal recommendation is make sure as your fabricating and fitting, make sure you don't do anything that would make it difficult to work on or do regular maintenance.

Can't wait so see what you do, don't be afraid to share some pics
 
You plan on street driving? I know the big blocks were wound up pretty good on the highway but the 12v behind a th400 would be worse I believe.
 
You plan on street driving? I know the big blocks were wound up pretty good on the highway but the 12v behind a th400 would be worse I believe.

You are right, a big issue with running those older transmissions like a th400 or a C6 is a couple of different things. No overdrive, no LC, but also the vacuum modulator would need a engine driven vacuum pump and you would have to fab up kick down linkage which can be a pain. Luckily for Rdeselle93, he already had a pretty stout nv4500.
 
Nephew 12v swapped his 83 C30 4x4, first with turbo 400 but that was to slow and trans finally let go, then Chevy nv4500 with 1st gen 12' clutch, ripped the centers out of 2 disc and snapped the input shaft, swapped in a 13' clutch using a Dodge bell housing and Dodge nv4500 with big input that's holding up pretty well
Personally I would have searched for a G56

Not much room between a mechanical fan and the radiator if you don't notch the firewall, if you want AC notching the firewall is probably necessary, his is non AC and the inner cooler is against the grill
 
I did a 91 chevy suburban Cummins Swap for a guy but I used a 47rh trans with the chevy 241 passenger side drop t case. IMO its easier to find a part on the shelf than a custom part for customers that don't know parts
 

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I did a 91 chevy suburban Cummins Swap for a guy but I used a 47rh trans with the chevy 241 passenger side drop t case. IMO its easier to find a part on the shelf than a custom part for customers that don't know parts
Somehow I always like your work.

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I did a 91 chevy suburban Cummins Swap for a guy but I used a 47rh trans with the chevy 241 passenger side drop t case. IMO its easier to find a part on the shelf than a custom part for customers that don't know parts

That is badass.
 
I did a 91 chevy suburban Cummins Swap for a guy but I used a 47rh trans with the chevy 241 passenger side drop t case. IMO its easier to find a part on the shelf than a custom part for customers that don't know parts

Awesome build! Looks very clean and finished.
 
I did a 91 chevy suburban Cummins Swap for a guy but I used a 47rh trans with the chevy 241 passenger side drop t case. IMO its easier to find a part on the shelf than a custom part for customers that don't know parts

Clean build man I like it
 
Somehow I always like your work.

Sent from my motorola one 5G using Tapatalk
Most folks that take advantage of me do too.
This job was done on the agreement of labor for labor
Cummins Swap for him (he owned 2 body shops)
Paint one of my trucks (Sold both body shops so never got my truck done)
Lesson learned Cash up front

That is badass.
Thanks
Awesome build! Looks very clean and finished.
I was trying to go as clean as possible owner Didnt want me to paint the firewall
I second that
:Cheer:
Clean build man I like it
:Cheer:
 
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