I am looking into putting a diesel into my 56 f100 truck. I have been thinking of a 5.7 diesel. Yes I am aware of the problems they had. I worked for a Pontiac-GMC dealer when they came out and later a indepent truck shop working on big rigs , but we still saw some olds and trucks with the 5.7 in them.

What are the advantages of a 6.2 or 6.5 NA engines over the 5.7? I do not intend to be pulling any thing larger than a 2 wheeled trailer with a riding mower. What I am looking for is fuel mileage. I have owned several diesel VW's from the orginal 52hp rabbit version to 2 TDI versions. With the Passat getting over 700 miles to a tank. Not the same thing I know.

My truck would be just a driver. Maybe a local show or such. Truck is in the planing stages but I would like to figure out the engine and tranny options so I can get to hunting parts.

Thanks all.

More power, more reliable, much easier to find parts for (5.7 stuff is museum material).
Mileage would depend on your tranny/rearend/tires and driving habits.

What about size. Is the 6.2-6.5 a much larger engine than the 5.7? I am open to sugestions on a tranny, gearing and whatever sugestions. I can use a auto or std tranny.

What about a Cummins 4BT (3.9 liter)? Sounds more like the engine you are looking for. I've heard several claims of 30+ mpg with this engine in a 1/2 or 3/4 ton pickup. They've been put into Fords before, so I'd imagine you could do it. Parts are plentiful, and the engines can be had pretty cheap (under 3k for a low mileage one).

That or a little Nissan Diesel, they're common, cheaper and lots of adapter plates available. But 4BT is a great engine all around.

One of the 4x4 mags had a piece on a jeep with the 4cyl cummings. It would top out at 45mph wide open. Not much of a daily driver there.

Maybe that was a 4B, I think the 4BT (turbo) is a significant step up power wise.

I think it was a NA engine, but I think the gearing was the thing.