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November 2007 4x4 Tech Questions - Techline

Willie Worthy | Writer
Posted November 1, 2007

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Question: I would like to convert my '91 Ford E-350 from a gas-guzzling 351ci V-8 to a four-cylinder diesel. I have an '86 Mitsubishi Fuso engine with 47,000 miles that runs beautifully. After that, I would like to convert it, of course, to four-wheel drive. Is there anyone who can help me with this conversion or supply conversion parts?
Frank Acello

Answer: Before you even think about this conversion, you should check and make sure such a swap is legal. Will it pass an emissions test? Within a year or so, Mitsubishi plans to shut down its engine shop and outsource engines due to fact that their current line of engines will not pass emissions testing. Your 21-year-old diesel engine, most likely, is not the cleanest-burning engine around.

The next thing is to find out what the parts availability situation is for this engine. My guess is that there are a lot of these engines still in operation, especially in Europe and Japan. One source for parts may be Tom's Truck Center, a Fuso dealer (888/507-5260).

I get the impression that this engine is used in some light delivery-truck and industrial applications such as forklifts. This means that there is a good chance that there may be an SAE-type bellhousing available that will make it easier to adapt to a standard transmission. However, you didn't say if your unit was a standard or an automatic. You may be better off using a matching Mitsubishi transmission, but then you're going to have the problem of adapting the transmission to the transfer case. In this instance, you might consider using a divorced NP205 transfer case. Yes, you would have to build another crossmember to hold the transfer case in place, but as it is, you're going to be building motor mounts and crossmembers to hold the engine in place anyway. I have never heard of anyone ever using this engine, and in fact can't seem to find much information on it. It's one of these swaps that reminds us that "just because you have a good engine, it doesn't make it a candidate for a good conversion."

Question: I see a lot of competitors in Top Truck Challenge 2007 with an NP203/205 transfer case. Is that a better setup than a 205 Chevy/205 divorced Ford? Will this give me any problems? If it works, do you know the gear ranges of the transfer cases?
Justin Folkman

Answer: The reason for the 203/205 combination is that the total overall length is so much shorter and lighter than using two separate 205s with a driveshaft or coupler between them. Off Road Design ( offers a kit that makes use of just the gear reduction unit of the 203 and bolts it directly to the 205 unit with a very narrow adapter plate. This gives the choices of a 2.00:1 or a 4.00:1 combination of low-range gear ratios (OK, in actuality the 203 is 2.01:1 and the 205 is 1.96:1).

Question: My '95 Grand Cherokee has an oil leak that seems to be coming from the oil filter. I have tried different brands of filters, and various stages of tightness with the filter, but it still leaks. Any ideas on how to solve this problem?
Anthony Smith
Los Angeles, CA

Answer: First, check to make sure that you didn't leave an old filter gasket behind on the filter mount. This can happen and will lead to an oil leak.

OK, the second thing to check is the oil-filter adapter that's mounted to the block. Take it off and lay it on a surface plate. OK, you don't have a surface plate handy. A pane of window glass works for this. If you can insert an 0.008-inch feeler gauge between the adapter and the glass, you have found the problem. That is all the warpage it takes to cause a leak.

The new adapter is under PN 53009219, and the gasket between it and the block is PN 53020461. Tighten the new adapter to around 50 lb-ft of torque, put on the new filter, and start the engine and check for leaks. Maybe you'll even want to check the oil level just to be on the safe side.

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