Diesel swap out - The 1947 - Present Chevrolet & GMC Truck Message Board Network

mecwpri · 10-31-2008, 07:18 PM

I have an original Chevy diesel, 1982 vintage. motor and trans are long gone, bought it that way because the body is really straight and rust free. I also have a 1985 chevy van, the 25 or 3/4 ton I think although it still has the 5 lug wheels, and it has been hit in the rear. I want to put the drivetrain in the pickup. I think the trans is a 400? how do you tell the difference in a 350 and 400 trans? My next problem is the trans crossmember, seems to be mounted too far forward in the truck for this setup, do I need another crossmember or is it possible to move it back? Also the trans out of the van has a fixed yoke where the truck had a slider driveshaft I think, how do I mod this to work?Next question is what can I expect when it comes to electrical mods to make the gas motor work? Any other helpfull hints would be nice, thanks guys!

James McClure · 11-01-2008, 09:17 AM

OK, first things first, slow and easy. Trans is definately a 400. 350's didn't come with a fixed yoke. 350 has a "square" pan on it and has a downshift cable on the right side. The 400 has no cable, just an electrical connector on the left side I believe. The connector is for downshift and the switch for that is on the gas pedal. As far as the drive shaft goes your going to have to use the van shaft and have the rear section modified by a machine shop to fit. The shaft will be the biggest issue. If I were faced with this swap I would get the eng and trans installed and running properly and then deal with the shaft and the "u" joints last thing just in case something needed to be shifted to get the fit right where the eng and trans were concerned. Crossmember is no biggy, just move it and drill new holes as necessary. Electrical will not be to bad. Alt wireing, starter wireing, fuel level wireing will all be the same. You may be able to use the power for the old injection pump to feed the gas motors ignition circut but I'm not sure if that wire stays hot when your in the start up mode. I think it does, just not sure. If ya need more info e-mail me and we can discuss it on the phone. I might have a shft you can use

jim

mecwpri · 11-02-2008, 03:54 PM

Thanks for the info, My shaft problem is that the van has a hanger bearing and the truck does not, I think. After some more looking I think the holes are already there for the crossmember to be moved back the couple of inches it will require. Also the motor mounts are different between the truck and van and the few years of difference in production so I had to do some swapping there to get things lined up and working. Should work on the crossmember after the race today on tv. Think the wiring will be the simple part now. The trans dipstick and motor oil fill tube will need to be changed out also, I cant close the hood as both of these items now interfere. Which side does the battery go on, I have the choice as the diesel had two, might just run two!

bills64riv · 01-07-2009, 08:42 PM

Quote:

Originally Posted by mecwpri

Thanks for the info, My shaft problem is that the van has a hanger bearing and the truck does not, I think. After some more looking I think the holes are already there for the crossmember to be moved back the couple of inches it will require. Also the motor mounts are different between the truck and van and the few years of difference in production so I had to do some swapping there to get things lined up and working. Should work on the crossmember after the race today on tv. Think the wiring will be the simple part now. The trans dipstick and motor oil fill tube will need to be changed out also, I cant close the hood as both of these items now interfere. Which side does the battery go on, I have the choice as the diesel had two, might just run two!

I have an 83 Diesel Van, and I am having a hard time finding where the 2nd battery would go. I found the one on the drivers side. Where else would it go? Seems like there is no room on the passengers side because of the A/C box. Thanks

James McClure · 01-08-2009, 04:44 AM

Bill: Battery #2 goes under the truck on the drivers side. Jim

10-31-2008, 07:18 PM	#1
mecwpri Registered User Join Date: Oct 2008 Location: Cheyenne, Wyoming Posts: 9	Diesel swap out I have an original Chevy diesel, 1982 vintage. motor and trans are long gone, bought it that way because the body is really straight and rust free. I also have a 1985 chevy van, the 25 or 3/4 ton I think although it still has the 5 lug wheels, and it has been hit in the rear. I want to put the drivetrain in the pickup. I think the trans is a 400? how do you tell the difference in a 350 and 400 trans? My next problem is the trans crossmember, seems to be mounted too far forward in the truck for this setup, do I need another crossmember or is it possible to move it back? Also the trans out of the van has a fixed yoke where the truck had a slider driveshaft I think, how do I mod this to work?Next question is what can I expect when it comes to electrical mods to make the gas motor work? Any other helpfull hints would be nice, thanks guys!

11-02-2008, 03:54 PM	#3
mecwpri Registered User Join Date: Oct 2008 Location: Cheyenne, Wyoming Posts: 9	Re: Diesel swap out Thanks for the info, My shaft problem is that the van has a hanger bearing and the truck does not, I think. After some more looking I think the holes are already there for the crossmember to be moved back the couple of inches it will require. Also the motor mounts are different between the truck and van and the few years of difference in production so I had to do some swapping there to get things lined up and working. Should work on the crossmember after the race today on tv. Think the wiring will be the simple part now. The trans dipstick and motor oil fill tube will need to be changed out also, I cant close the hood as both of these items now interfere. Which side does the battery go on, I have the choice as the diesel had two, might just run two!

01-08-2009, 04:44 AM	#5
James McClure One shot, one kill. Join Date: Dec 2007 Location: Saratoga Springs NY Posts: 859	Re: Diesel swap out Bill: Battery #2 goes under the truck on the drivers side. Jim __________________ 1984 K20 350M engine with 465,000 miles. Well, it's finally done!! Almost 2 years of work, but it was really worth the effort. Little stuff left to do is mount winch, wet sand & buff out and build belly pan\running boards. Body work takes lots and LOTS of beer!!!! God, Guts and Guns made America and God, Guts and Guns will preserve it! The worst thing you could do is get into my sights, but that don't matter, you'll never know it, cause you'll never hear the shotJim or Paladin whichever you choose.

11-01-2008, 09:17 AM	#2
James McClure One shot, one kill. Join Date: Dec 2007 Location: Saratoga Springs NY Posts: 859	Re: Diesel swap out OK, first things first, slow and easy. Trans is definately a 400. 350's didn't come with a fixed yoke. 350 has a "square" pan on it and has a downshift cable on the right side. The 400 has no cable, just an electrical connector on the left side I believe. The connector is for downshift and the switch for that is on the gas pedal. As far as the drive shaft goes your going to have to use the van shaft and have the rear section modified by a machine shop to fit. The shaft will be the biggest issue. If I were faced with this swap I would get the eng and trans installed and running properly and then deal with the shaft and the "u" joints last thing just in case something needed to be shifted to get the fit right where the eng and trans were concerned. Crossmember is no biggy, just move it and drill new holes as necessary. Electrical will not be to bad. Alt wireing, starter wireing, fuel level wireing will all be the same. You may be able to use the power for the old injection pump to feed the gas motors ignition circut but I'm not sure if that wire stays hot when your in the start up mode. I think it does, just not sure. If ya need more info e-mail me and we can discuss it on the phone. I might have a shft you can usejim __________________ 1984 K20 350M engine with 465,000 miles. Well, it's finally done!! Almost 2 years of work, but it was really worth the effort. Little stuff left to do is mount winch, wet sand & buff out and build belly pan\running boards. Body work takes lots and LOTS of beer!!!! God, Guts and Guns made America and God, Guts and Guns will preserve it! The worst thing you could do is get into my sights, but that don't matter, you'll never know it, cause you'll never hear the shotJim or Paladin whichever you choose.



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