I have a 1964 J-200 Gladiator project that I am going to start on soon. It's been sitting in a field for quite some time, but the frame and body are all in pretty good shape as the engine was seized long before it got too beat up. I'm planning on a resto-mod. A 5.3 LS swap and a 4-inch lift with 35" tires. I'm considering swapping the closed knuckle axles with the Dana 44's from a later model J10, as well as the power steering box and the air conditioning system. I'm also planning on keeping the stock 4 speed T98 trans and the Dana 20 transfer case.
My question is how much if any of the later generation j10 and j20 parts fit the early models? For the lift, I was thinking about swapping to a kit designed for a J10, since there are a lot more options, but will the leaf shackles and brackets fit an early frame with minimal modification? The same goes for the steering and the axles.
Thanks!
Truck Modularity
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tgreese
- Posts: 7191
- Joined: Fri Jun 08, 2012 6:31 am
- Location: Medford MA USA
Re: Truck Modularity
Welcome from Boston.
There are a lot of differences, too many to list. Not modular. Starting with the running gear, the T-98 is fairly obsolete, replaced by the T-18 just a few years later. V8 Jeep trucks have a unique T-18 transmission that has a very long input shaft and either a longer bell or thick transmission adapter. This truck was a 230 OHC six originally, and the engine compartment is designed for an inline 6. The V8s are shorter and wider than the 6s, and Jeep put the V8 at a more forward location in the engine compartment, then filled the gap by extending the front of the transmission.
You will need to adapt the T-98 to your Chevy engine. Without that special V8 transmission, you will have to move the transmission forward so the stalk comes up under the dash. You can heat and bend the stalk, but it won't be like the original truck.
The suspension mounting is different. Pretty sure this truck has "post mount" springs, and there are very few options for that. You can cut the mounts off and weld on everything from a later frame. Lots to do to make it work. A later frame and axles might be a better option.
These first generation trucks are missing a lot of the refinement you'll find in the later trucks... bad axles, bad brakes, bad steering, bad engine, and a comparatively crude execution. Many of these trucks are horribly rusty, especially the beds. If this truck has intact body steel, I'd consider either fixing it up with a similar 6-cylinder engine and enjoying it for the old truck that it is now, or finding a frame and drivetrain donor and swapping the body onto the later chassis. The '70s trucks are way more advanced than these earliest J-trucks, and you will have a lot to change if you want to update using this truck's chassis. Note that the early and late Jeep truck wheelbases don't match exactly, so I believe you'll have to adjust the rear axle position some if you use a Jeep chassis donor, as well as moving the body mounts on the frame.
There are a lot of differences, too many to list. Not modular. Starting with the running gear, the T-98 is fairly obsolete, replaced by the T-18 just a few years later. V8 Jeep trucks have a unique T-18 transmission that has a very long input shaft and either a longer bell or thick transmission adapter. This truck was a 230 OHC six originally, and the engine compartment is designed for an inline 6. The V8s are shorter and wider than the 6s, and Jeep put the V8 at a more forward location in the engine compartment, then filled the gap by extending the front of the transmission.
You will need to adapt the T-98 to your Chevy engine. Without that special V8 transmission, you will have to move the transmission forward so the stalk comes up under the dash. You can heat and bend the stalk, but it won't be like the original truck.
The suspension mounting is different. Pretty sure this truck has "post mount" springs, and there are very few options for that. You can cut the mounts off and weld on everything from a later frame. Lots to do to make it work. A later frame and axles might be a better option.
These first generation trucks are missing a lot of the refinement you'll find in the later trucks... bad axles, bad brakes, bad steering, bad engine, and a comparatively crude execution. Many of these trucks are horribly rusty, especially the beds. If this truck has intact body steel, I'd consider either fixing it up with a similar 6-cylinder engine and enjoying it for the old truck that it is now, or finding a frame and drivetrain donor and swapping the body onto the later chassis. The '70s trucks are way more advanced than these earliest J-trucks, and you will have a lot to change if you want to update using this truck's chassis. Note that the early and late Jeep truck wheelbases don't match exactly, so I believe you'll have to adjust the rear axle position some if you use a Jeep chassis donor, as well as moving the body mounts on the frame.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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fiddlemahn
Topic author - Posts: 3
- Joined: Fri Nov 20, 2020 6:54 pm
Re: Truck Modularity
Thanks for the reply, @tgreese!
For the engine conversion, I was planning on going with a kit from Novak Jeep Conversions. https://www.novak-adapt.com/ They have a kit for a T98 to LS engines, LS engine mounts for first-gen FSJs, as well as a bunch of other parts like transmission and transfer case rebuild kits.
As far as the aftermarket is concerned, there are definitely more options for the newer trucks. I will admit the much easier route would be to just put a rhino grill on a newer J10 with some mods, but what's the fun in that? (lots). If I go with this older J-200, I would have to go the frame-off restoration route, so I wouldn't mind a little bit of fabrication to give it the much-needed updates.
Are the frames between the newer and older trucks at least the same width? If so, then it doesn't seem too hard to swap the hangers from a newer truck, as well as axles, brakes, and other things.
Not quite sure which route to take, although a frame swap with a newer truck does sound enticing.
Thanks!
For the engine conversion, I was planning on going with a kit from Novak Jeep Conversions. https://www.novak-adapt.com/ They have a kit for a T98 to LS engines, LS engine mounts for first-gen FSJs, as well as a bunch of other parts like transmission and transfer case rebuild kits.
As far as the aftermarket is concerned, there are definitely more options for the newer trucks. I will admit the much easier route would be to just put a rhino grill on a newer J10 with some mods, but what's the fun in that? (lots). If I go with this older J-200, I would have to go the frame-off restoration route, so I wouldn't mind a little bit of fabrication to give it the much-needed updates.
Are the frames between the newer and older trucks at least the same width? If so, then it doesn't seem too hard to swap the hangers from a newer truck, as well as axles, brakes, and other things.
Not quite sure which route to take, although a frame swap with a newer truck does sound enticing.
Thanks!
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tgreese
- Posts: 7191
- Joined: Fri Jun 08, 2012 6:31 am
- Location: Medford MA USA
Re: Truck Modularity
You're welcome! I am very familiar with the Novak site and what they list there. They have a kit to adapt the M715 military truck T-98 to a GM bellhousing. https://www.novak-adapt.com/catalog/ada ... /kit-c715/ Civilian trucks are so-called J-trucks, and they are different from the military trucks. If they have a page with an adapter that they say will work with the civilian truck transmission, please include that link.
Novak specifically does not include the early J-truck T-98s. If they could, I believe the Novak page would include them. Even then, it's not really a "kit" but a cast aluminum adapter that mates the Jeep transmission to a GM bellhousing. Advance Adapters may have something to adapt the J-truck T-98. If they do, it will not address the difference between the transmission made for the 6-cylinder and the V8. You will still need to move the transmission forward so the shifter is under the dash, and you will have cut a new hole, then heat and bend the shifter to reach rearward from under the dash. This issue has been covered many many times here and at IFSJA, and you can learn more by searching and reading these older posts.
Frame width is the same, track width is pretty much the same. The body shell does not change significantly from beginning to end. The early beds have differences from the later ones, with a single wall, round tail lights, and a different wheel opening location that goes along with the changed wheelbase.
Not trying to rain on your parade, but these trucks were around for about 25 years, and they went through four different corporate owners in that time. The body style did not change much, but the mechanical systems and major components changed a lot. Plus the production numbers were never very high, so modern parts and accessory support is sparse.
Novak specifically does not include the early J-truck T-98s. If they could, I believe the Novak page would include them. Even then, it's not really a "kit" but a cast aluminum adapter that mates the Jeep transmission to a GM bellhousing. Advance Adapters may have something to adapt the J-truck T-98. If they do, it will not address the difference between the transmission made for the 6-cylinder and the V8. You will still need to move the transmission forward so the shifter is under the dash, and you will have cut a new hole, then heat and bend the shifter to reach rearward from under the dash. This issue has been covered many many times here and at IFSJA, and you can learn more by searching and reading these older posts.
Frame width is the same, track width is pretty much the same. The body shell does not change significantly from beginning to end. The early beds have differences from the later ones, with a single wall, round tail lights, and a different wheel opening location that goes along with the changed wheelbase.
Not trying to rain on your parade, but these trucks were around for about 25 years, and they went through four different corporate owners in that time. The body style did not change much, but the mechanical systems and major components changed a lot. Plus the production numbers were never very high, so modern parts and accessory support is sparse.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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fiddlemahn
Topic author - Posts: 3
- Joined: Fri Nov 20, 2020 6:54 pm
Re: Truck Modularity
tgreese wrote: ↑Sun Nov 22, 2020 6:13 pm You're welcome! I am very familiar with the Novak site and what they list there. They have a kit to adapt the M715 military truck T-98 to a GM bellhousing. https://www.novak-adapt.com/catalog/ada ... /kit-c715/ Civilian trucks are so-called J-trucks, and they are different from the military trucks. If they have a page with an adapter that they say will work with the civilian truck transmission, please include that link.
Novak specifically does not include the early J-truck T-98s. If they could, I believe the Novak page would include them. Even then, it's not really a "kit" but a cast aluminum adapter that mates the Jeep transmission to a GM bellhousing. Advance Adapters may have something to adapt the J-truck T-98. If they do, it will not address the difference between the transmission made for the 6-cylinder and the V8. You will still need to move the transmission forward so the shifter is under the dash, and you will have cut a new hole, then heat and bend the shifter to reach rearward from under the dash. This issue has been covered many many times here and at IFSJA, and you can learn more by searching and reading these older posts.
Frame width is the same, track width is pretty much the same. The body shell does not change significantly from beginning to end. The early beds have differences from the later ones, with a single wall, round tail lights, and a different wheel opening location that goes along with the changed wheelbase.
Not trying to rain on your parade, but these trucks were around for about 25 years, and they went through four different corporate owners in that time. The body style did not change much, but the mechanical systems and major components changed a lot. Plus the production numbers were never very high, so modern parts and accessory support is sparse.
Novak has a kit for the J-Truck T98 https://www.novak-adapt.com/catalog/ada ... gm/kit-c5/ apparently this adapter is 1 3/4" long and it's used on top of the existing plate that came bolted on at the factory. I guess it wouldn't hurt to give them a call about placement.
Thanks for the info! Much to think about for this project going forward.