400 cummins information

I built a 290 small cam to a 400 by the CPL book. Also built an old big cam to a low flow once. Low flow blocks were scarce and expensive at the time. After having it decked and machined for lower press fit liners noticed the block was different in the water pump area. Ground it out as close as possible as the other. Glad that worked, already had a boat load in it.
Just saying you can not always go by that.

 

The serial number should be stamped in the block at the left front just below the head gaskets.
It might be stamped at the left rear just below the head gaskets.
Cummins should be able to tell you more about the engine from that.

If the 90 has STC injectors I would pass on it they are expensive and problematic

 

I have a 444xt that is low flow cooling. Haven't found much info about converting it to high flow. I have a friend that has been a mechanic long enough to remember most things about the engine but the conversion is a little fuzzy. He does remember that there was a procedure to do it though.

So far the low flow has been working fine, but I'm not pulling loads

 

Probably owe an " Uncle " to 81pete even though he did not bend my arm behind my back. Some of my information is a little clouded from memory. I do remember the Spirit of 76 Peterbilts. They were red white and blue. He must have an engine from one of those. Ha Ha.
I rebuilt a 444 in a small grill Astro. Someone in New York did the deal. It ran hot and scored the pistons.
It had one side of the water rail ground down close to the O-rings in order to clear the jakes. They over looked the water rail grommets to the head are restricted on the low flows. It still had four of them. Customer also requested to replace the broken temperature gauge. Like to drive anything I do major work on but I could not put my hands on the paper work and something seemed a little flaky. They came back to town and paid cash, 5's 10's and 20's except $800. Had to go to Western Union to get that. But this is cash. Yes and when I gave you the price that is the cash price. You need $800 more dollars.
Now I want to ride in it on a test drive, run it hard a little bit, and then look it over. He had an empty trailer on the Interstate about 5:30 on Friday coming out of town. Skipped a lot of gears being empty but always as smooth as a car with an automatic. I thought nothing when he skipped another gear and went to the big hole, far right and back. Traffic was moving and we were right there with them strolling. The lane opened up and he let off? Pushed the stick to the dash and the Cummins started rattling. Eased me back in the seat and we were passing four wheelers like fence posts.
RocketScott thanks for reminding about some good times. If it is not broke don't fix it just maintain it.

 

You really should try to get the CPL numbers from those engines or the serial numbers and find out exactly what they are. Either one could be repowered and you won't know unless you have that information.

Both trucks to me seemed kind of expensive, but they do look like they're clean and they probably have history and maintenance records and recent work done to them I assume. I would also assume they have records of rebuilds and recent work because that's some miles for those engines.

As far as engines, the later model engine was the most improved. Assuming they are the correct engine for that model year, and depending on what you want to use it for I would go for the 1990.

The 1990 has the newer style rear suspension that still is in use today. The older air ride is okay but the newer style is definitely improved and it's probably easier to find Rears and cut offs and that type of thing if you need them. There are probably more parts around in general for the 1990 than for the older truck. I can't tell you about the exact 1990 year, but my truck is a 95 and Freightliner has all complete schematics for everything that you can get online. I don't think they have that for the older trucks although I don't know what year is the cutoff.

Also the 1990 has the nice unibilt sleeper. I always hated the other sleeper types because the seat always hit the back of the cab. The unibilt is much better it has more room and it's just more comfortable. And it isn't just the sleeper it gives the cab more room. And if the 1990 has a tilt wheel and the older truck does not, it may sound stupid but that wheel gives you an infinite range of adjustment and is really way comfortable compared to a stationary wheel. That is a huge difference in driving comfort.

The older truck looks cool, but it probably will be harder to back up without the set-back front axle like the other truck. I guess it really depends what you are looking for, but I would go for the 1990 for a work truck.

The older truck is nice for a play truck or I guess if that's your style. But if the older truck has an early low-flow engine, they had some problems and the later model would probably be a better choice.

Now if the 86 was a big cam 3 with high flow, that would be a good engine choice.

 

@Lysdexis

What did you end up doing?

 

It’s easy enough to change from low flow cooling to high flow

 

I have heard that it can be expensive to change them over, and that you need exactly the right parts.

That's the way that I understand it anyway.

 

Depends if it’s an 88nt it’s a little higher. But the low flow does fine if you keep the radiator clean and don’t try to juice it too high