Starting a 4bt swap

[Safaritow]

Oh, Man is this site great. I have been trying to research a 4BT swap for my M-715
So glad to see other people doing the same. I’m getting my Frito-Lay truck Tuesday And can’t wait to start. I’m hoping my set up will work. I would like to run it buy you before we get started. If you for see any uses that might not work please let me know,
I have a 1968 M-715 Kaiser we are doing the 4BT swap with the 400 tranny. I’m hoping the transfer case will mate. We have 2 ½ ton axles under it with 6:72 gears and 52” tires have no idea what top speed will be. But I’m hoping it will pull like no tomorrow. They make a fuel/tool transfer tank that will hold 90 Gallons that I can set in the bed; I thought that this would work for a fuel tank. Any help would be great. We are going to take pics as we go. Thanks for the help

[MoparNorm]

What case is in the Jeep? Is it a NP205?
Here are a few examples of mounting the 205 to a TH400, unfortunately I cannot remember who had these adapters, but they are still available, try a yahoo search.



MN

[Safaritow]

How do I tell the difference between a 200 and a 205? If anyone knows who to get the adapter from that will help. Thanks

[Safaritow]

Ok, I went out and looked under the truck and it has a divorced transfer case must be a NP-200 with a short driveshaft from the tranny to the case. Will I have to move the transfer case back with the 400 installed? Thanks

[slozukimc]

Ok, I went out and looked under the truck and it has a divorced transfer case must be a NP-200 with a short driveshaft from the tranny to the case. Will I have to move the transfer case back with the 400 installed? Thanks

Is the rear output of the case centered or offset to the passengers side? 200 is offset 205 is centered.

Mike

[Sickcall]

Dodge used alot of divorced 205's so don't make the assumption it's a 200 just because its divorced.

The 4bt sounds like a great engine for a stock M715 but it may be underpowered for duece axles and 52's. The M715 has a large engine compartment and it sounds like a 6bt may be a better choice. This is just my opinion, having never driven a 4bt, just looking at the HP to weight ratio.

[Charles Talbert]

Sickcall is correct

A 6BTA would be much more suitable for the rig you are creating. It will fit in a 715 engine bay, you will be much better pleased with it in the end. A 4BTA will be in a strain much of the time, this situation isn't what you want as it will of course limit vehicle performance. It will also significantly shorten the life of a smaller engine if it runs under a constant strain. Just some things to think about. Good luck with the project.

[Gordon Maney]

A 6BTA would be much more suitable for the rig you are creating. It will fit in a 715 engine bay, you will be much better pleased with it in the end. A 4BTA will be in a strain much of the time, this situation isn't what you want as it will of course limit vehicle performance. It will also significantly shorten the life of a smaller engine if it runs under a constant strain. Just some things to think about. Good luck with the project.

Charles, how would you feel about the 4BT in that truck if it retained the stock axles?

[Charles Talbert]

Depends on the end use you have in mind

Charles, how would you feel about the 4BT in that truck if it retained the stock axles?

It sounds obvious this guy would like to end up with a high performance pulling vehicle since he's going to the trouble to install axles this heavy along with the other changes from stock. It's pretty easy to overwhelm the engine capability with a set up like this, tall tires & all. After doing a good many repowers & having some experience under my belt, I personally wouldn't recommend less than a 6BTA in the application. The fact that he intends to use an automatic transmission is certainly a factor as that set up won't perform well at all if under powered.

Gordon, you ask about the 4BT in a stock truck. I would recommend a 4BTA in that application simply because there is more lead way to work with tweaking out more power with an aftercooler in place. I have used a 4BTA in a 715 that worked out great. It was a driver capable of 70 MPH. The 4BT is OK if it suits the owner. I just like having all avenues open if I'm going to the trouble & expense to do a diesel repower. This is why we install the 4BTA's instead. I have nothing against the 4BT, I'd install one in a minute if someone asked us too.

[MoparNorm]

Is the rear output of the case centered or offset to the passengers side? 200 is offset 205 is centered.

Mike

If it is a stock truck, it should have the NP200 in it. That's a 205 in my photo with the TH400 adapter, the 200 does not have the aluminum tail cones, it's nearly identical to the 201 except for the off-set rear output.
MN

[Safaritow]

Just got in with the Frito-Lay truck

Just got in from NC with the frito-lay truck.
THAT WAS FUN
It runs great. The engine sets in the Frito-lay truck on a angle does it have to stay that way? And do I have to move the transfer case back or will it stay in place? Thanks again

[JimmieD]

Only the GM/Cummins installs sit on an angle. No, it doesn't have to stay that way unless you use GM drivetrain. You can fab your own engine mounts.

[slozukimc]

Which way does it lean?

Only the GM/Cummins installs sit on an angle. No, it doesn't have to stay that way unless you use GM drivetrain. You can fab your own engine mounts.

I haven't gone to look at the Frito van for my swap yet.....Which way does the engine tilt in the stock setup? Top toward which side?

Mike

[JimmieD]

I'm looking at a pair of 4BT Cummins/GM stepvan engine mounts here and it looks like it tilts toward the passenger side. Can't remember why though....?

[Safaritow]

Jimmie is right tilts to the right, But the tranny looks like its straight. Monday we are going to pull the engine and tranny out. I guess we will see what works for the install. Will a late model turbo fit on the 4bt?