86 K20 Cummins swap TH400 ?

[MikeHolc]

Hi, first post here, I googled what im doing but all the posts were old. 2010 some older. Im sure things changed since then.

I want to Cummins swap my K20, 6in lift on 35s , can i use the TH400 with the right converter and mods? Or should I be looking for a 4L80? Its not a everyday driver, weekends and when it's cool out, spring and fall. Or should I make it a 5sp? Where should I go with that? What 5sp? I just want to put it all together so its a working swapped truck. Yrs down the rd I can change things, add power and maybe do different trans,
Any advice would be great
Thanks

 

[PrairieDrifter]

Not a whole lot of Cummins swap guys here, that are regulars anyways. I'm in the middle of my first swap, so I only know what I've done and the research I've done.

I would recommend against a turbo 400. Maybe a built 4l80 would live, but I am not sure, couldn't be any worse than the dodge autos of the same era lol. You would have to have an auto built pretty much specifically for a diesel application though.

Allison autos came behind them. That would probably be the best choice for an auto. Out of buses or medium duty trucks.

If going a five speed manual I would stay away from the getrag, some people like them though.

Nv4500 minimum, nv5600 and g56 are the best options but are spendy.

But you should also consider that running any trans that didn't come behind a Cummins at some point, will need an expensive adapter setup and can cause headaches.

I'm going a little different route, overkill, but I'll be towing with mine and I usually overkill everything lol. I'm doing an Eaton 6 speed swap. Out of like a 90's bus/medium duty.

Check out farmstrong inc. This year they released a squarebody Cummins swap kit. I ordered the engine mount kit but not the trans because they didn't offer an Eaton kit. Very nice stuff and heavy duty. The summit kits and those kinds work, but they're ugly and not the best system. I would recommend against the Cummins to Chevy motor mount kits at least. And poly mounts should be avoided.

Farmstrong uses factory 5th gen isolators, if not a fan of the aluminum you can also use 4th gen cast isolators. Much better than the early trucks.

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Eaton 6 speed to getrag five speed difference. Getrag is very similar in size to the sm465.

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[PrairieDrifter]

Also how you use the truck is important. If just a cruiser, a getrag 5 speed, nv4500 or a 4l80 or even a built dodge auto may be just fine for you, especially considering you would need an adapter setup for the 4l80.

 

[MikeHolc]

Not a whole lot of Cummins swap guys here, that are regulars anyways. I'm in the middle of my first swap, so I only know what I've done and the research I've done.

I would recommend against a turbo 400. Maybe a built 4l80 would live, but I am not sure, couldn't be any worse than the dodge autos of the same era lol. You would have to have an auto built pretty much specifically for a diesel application though.

Allison autos came behind them. That would probably be the best choice for an auto. Out of buses or medium duty trucks.

If going a five speed manual I would stay away from the getrag, some people like them though.

Nv4500 minimum, nv5600 and g56 are the best options but are spendy.

But you should also consider that running any trans that didn't come behind a Cummins at some point, will need an expensive adapter setup and can cause headaches.

I'm going a little different route, overkill, but I'll be towing with mine and I usually overkill everything lol. I'm doing an Eaton 6 speed swap. Out of like a 90's bus/medium duty.

Check out farmstrong inc. This year they released a squarebody Cummins swap kit. I ordered the engine mount kit but not the trans because they didn't offer an Eaton kit. Very nice stuff and heavy duty. The summit kits and those kinds work, but they're ugly and not the best system. I would recommend against the Cummins to Chevy motor mount kits at least. And poly mounts should be avoided.

Farmstrong uses factory 5th gen isolators, if not a fan of the aluminum you can also use 4th gen cast isolators. Much better than the early trucks.

You must be registered for see images attach

You must be registered for see images attach

Eaton 6 speed to getrag five speed difference. Getrag is very similar in size to the sm465.

You must be registered for see images attach

Ok thanks ill look into it. Just a toy. Its just a toy. I almost considered swapping the chevy cab to the dodge frame and have a little more modern suspension. Ill have to look at the frame better when I pull the body off dodge to remove the engine/trans

 

[PrairieDrifter]

Ok thanks ill look into it. Just a toy. Its just a toy. I almost considered swapping the chevy cab to the dodge frame and have a little more modern suspension. Ill have to look at the frame better when I pull the body off dodge to remove the engine/trans

Dodge isn't famous for their good front ends lol. 1st gen would be the best bet.

Also forgot about the ford offerings, zf5 and zf6, seems to be popular.