4BT VS a carbed 318

[Lonesome7.3]

I am just kicking this idea around here so do not pass judgment too quickly. I have a 1972 Dodge D200 with a 318 and 727 that I am pretty much stuck with. (It has been in the family since it was new.) Do not get me wrong, I do love that old truck. But an all original 3/4 ton gasser does wear on my patience quite a bit. I would love for the truck to appear original outwardly, but have more modern and reliable stuff underneath. I can repair a diesel engine a lot better than I can this old gasser. So the way I see it, this old and reliable stock 2BBL 318 most likely puts out the same if not less power than a stock Cummins 4BT. So I figured with a few mild mods and a good overdrive transmission a 4BT would do this old truck nicely and get me down the road with fewer 30 something year old issues to correct every week. Feel free to chime in. What would the pro’s and con’s be on swapping out that old low mileage 318 for a 4BT?

[Lonesome7.3]

By the way, I already have an early 90’s Dodge donor truck with a Cummins 6BT in it. The 6BT is slated for another project. But everything else from the truck can be used to support a 4BT swap into the old D200.

[raunch]

You might have to do a body lift to fit the 4bt under the hood.

[Lonesome7.3]

Really? I do nto see much difference between the 72 gasser and the 90 something with a Cummins.

[NH2112]

I'd probably consider something like a Howell EFI setup, MSD ignition, and maybe a cam to wake the old 318 up a bit, assuming it's in good enough shape to benefit from the mods.

IIRC in 72 the 2bbl 318 was rated close to 200HP, my 76 & 77 were both around 160 and that was after they changed the way in which HP was measured. Most 4BTs from bread trucks, gensets, and other industrial applications were good for about 110HP, if it has the inline Bosch pump anything that increases power in a 6BT will work for the 4. If it has the rotary Bosch pump I'm not sure what works for performance upgrades. AFAIK the inline pumps are good for up to about 250HP and 400lb-ft. A friend put one in an 84 C2500 several years back, installed an Allison from a wrecked DMax and standalone computer, and went with the tallest gears available (3.30ish, I think) and was getting over 30mpg average.

[Lonesome7.3]

My plan right now is to upgrade the old 318 a bit when I rebiuld it. But I would like to consider the possibility of converting it first. I prefer having an oil buner under the hood.

Your friend's biuld sounds interesting and costly. The Allison had to be a ton of money. What kind of highway speeds does he reach at what RPM? That is my biggest concern. I want to travel down the highway at a reasonable RPM and with a four cylinder pulling a trailer I have some concerns.