My 78 E150 is in need of a new engine. It currently has a 300-6, bone stock, and a c6 auto with a 2.75 rear end. It's suffering from extreme low oil pressure, with a pretty bad lifter noise especially on startup so I know it doesn't have much life left.
My first option is to get another 300-6, rebuild it with a little hotter of a cam, and set it up for a 2BBL and EFI dual manifolds, then just swap them out. This would be the cheapest and fastest option, since I could still drive it during the rebuild and then swap it in a weekend.
My second option is a Mercedes OM617 5cyl turbodiesel and four speed auto. This engine makes almost the exact same power on the exact same curve as the 300-6, but the turbo compensates for high altitudes and the mileage will be a bit better. I can get a whole trashed car for $1200-$1500, and nearly make that back parting it out. This swap would be the most complex, and the van would be down for about a month, but that engine is known to go 500,000miles+ very reliably. Turning it up costs money, but I also have some experience with this engine since I'm currently putting one into my Courier. The compact packaging makes this engine easy to swap into the cramped van engine compartment. It's also a high speed diesel, governed at 4300 from the factory, but able to handle nearly 5500 reliably.
My final option is a Cummins 4BT, 3.9l turbo four cylinder. It's a bit harder to fit, since it's tall and I'll have to make a custom manifold to fit the turbo in there. It's also a bit more pricey, with the engine by itself running $1500-2500, and I'm not sure I want to put that much into this van. It's also a low rpm engine, governed at 2400rpm typically, although some people have turned up the governor on them. I'd probably run a 700R4 trans behind it, since that was a very common combo to find in bread trucks. It's also very heavy though, a few hundred pounds more than the 300-6, but it'll deliver pretty decent mileage, 22-25mpg vs current 15-16.

 

300 I6!

1. It's a very good reliable workhorse
2. Time
3. Smog inspection/future sale issue- itwould have to go to a federal referee station forever because of the swap!

 

Only if CA's absurd I/M program is brought here. I don't intend to ever live in a state that follows the same program.

 

KISS - Keep It Short and Simple

Build yourself another 300 and be done with it.

 

The old 300 was a dog, a single carb is just not efficient, obviously 2 cylinders get more fuel than the other 4, the only way for them is the EFI, and the late EFI 300 was bad az, many truck guys did a few mods and raced theirs. A friends 95 E-150 was getting 24 MPG with the C-6 300 in it, not now but has 340,000 miles on it, still going too.
The diesel is the way to go if you plan on keeping it and driving, talking trips to get real use for all the trouble you'll put into it, I'd do it to mine if the money was available, slam me a 5.9 Cumins in mine.

 

Unfortunitely that's not a California only law, that is a federal statue that each state must enforce.

 

Gotta love the 300 I6, but the Mercedes swap sounds very promising.
Is the trany with it an OD?

 

It's actually not an OD. The Mercedes diesel love to rev, I got to drive mine around in the car before I tore it all apart, and the power is definitely different than your typical diesel. There is a little lag off the line due to the turbo and fuel pump setup, but once the boost hits it's off like a rocket. Shifts were typically 4300rpm, and 65mph cruise in the factory setup is about 3000rpm. The funny part is that the acceleration rate seems constant once the boost is on, all the way from about 15mph to 80mph.
There's a reason I chose that engine for my Courier swap.

 

Thats funny, The IDIs will float a valve after 4000 RPM.

I think that one may be your best bet.
Whats the power/torque and at what RPMs?

 

Typical numbers are 125hp and 170ft/lbs, in stock trim at 12psi. I haven't been able to find what rpms those numbers are at, but I'm going to dyno my Courier this summer so I'll have some info on a modded and intercooled one.

 

Thats it? HP is the same but is that not a large drop in torque over the 300?

 

That year 300 made about 223ft/lbs when new at sea level. I'm at about 4800ft here, and in the last month drove the van from here to the central CA coast and back. The power change was more than noticeable, it was incredible. It could actually move itself. Coming home, I went over a pass on US93 that was 7700ft. It was floored, doing 20 in 1st and threatening to slow further. Given the altitude here, the Mercedes engine would actually have more power since the turbo would compensate for the altitude.

 

You seem pretty in tune with that Mercedes motor, so that would be my vote.

 

At 4800ft I would go with the Mercedes. I voted for the 300 before reading this and now wish I could change my vote.

I just have to say it: 7700ft, steep pass, C6, 2.75s and a worn out 300 I6 just has " EPIC FAIL" written all over it.


What I would do in your spot is get a wrecked police car ( 00-03 would be the best, but 92-99 would work great too. 04+ has drive by wire and I would stay away from it) and swap the 4.6 and 4 speed OD auto in. They are a very tough combo, I have yet to kill my 4.6/4R70W or my 6.8/4R100 and I really have tried.
You would take at least 5 seconds off you 0-60 too.

If you have the 8.8" rear you could swap the police interceptors gears in. 3.08, 3.27 and 3.55 are all factory options, LS and Non LS, it depends on what the PD ordered it with. If you got lucky with a car with 3.55s you pull a small camper up that same pass and do it faster, with the same or less gas.

Just a thought, I am a big fan of the Modular engine family, they rock.

 

Fords in Fords, especially if you ever decided to make yours a 4x4 .