Big cam 3 400

The flywheel is definitely not interchangeable but it’s likely drilled for the same size clutch or possibly has 2 sets of holes to bolt the clutch on. the center clearance in the flywheel might be different and could interfere with the damper spring in the clutch disk.

 

As far as your engine mounts could go either way. Might be surprisingly interchangeable or nothing close.
I have seen both ways. If the cummins came from a kw you will probably be pretty close if not the same.

 

Some did come with a 15 inch clutch but uncommon. He can figure that out rear quick.

 

The inlet and outlets on the radiator tanks are different between Cat and Cummins. Some Cummins used two bolt rear mounts and others used one bolt solid mounts. I do know if it was old enough to have had a 1693 in it. Nothing is remotely close for a 855 Cummins swap as far as mounts, radiator or position in frame. I’m up against that trying to put a BC in my ‘73 Pete 352 that had a 1693 long ago.

 

A lot of the older radiator tanks were made to be a universal fit so to speak. They may have holes and threaded bungs in different places with bolted on plates covering the hole not used. All you have to do is find the right hose inlets and gaskets that bolt on and cover the hole that is now not used. Some engines may pull from left on tank were Cummins pulls from right and so on.

 

This what i’m referring to. This is the radiator in the 352. It is 1050 square inches. Pretty close to Kw’s size I recall. You can see the plate I’m referring to on the top tank. The cat pulled from the left and a Cummins is going to use that right side hole. On the bottom the Cat pulled from both sides and Cummins will only use the right side. So I have to cover left hole with a plate. Also cats used bigger dia. hoses to water pump and thermo housing than Cummins.

This was the setup for a 1693. Not sure if the 3406 was same.

 

I’m not sure why Cat pulled from the bottom with two outlets. I was told it may be because it had a brake saver and needed more cooling flow faster. But this truck has no signs of ever having the controls for it in the cab anywhere. No scars from the extra trolly valve to be found.
Problem I have is the engine has been MIA for 32 years and all the folks I know that had any first hand experience with 1693’s or this truck have passed on.

 

Engine mounts were different from Cats to Cummins back then. They were much bigger and different shape. But like I said not sure on the 3406.
When the engine was removed back in 1990 the rear mounts were removed as well.
The truck and engine were pushed back into a dark corner of the shop and shady family members on my uncles married side “borrowed” everything years ago. So I’m sure statute of limitations are up. Lol!

 

I don't know about the caterpillar but the thermostat housing on the Cummins is on the right hand side and the lower hose to the radiator is also on the right hand side.

My truck had a series 60 on it so the lower radiator hose on the right fits but I had to run a pipe across the top to connect to the outlet on the top left for the radiator. Nothing wrong with that I think that's just how the radiators are even for the regular Cummins engine. Can't tell you anything about the caterpillar though.

No, that's crazy.