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.

 

[pennsylvaniabo]

personally i have never been impressed by a 318. In reality you could take the money of the 4bt and modify the 318 to put up some decent #'s but then you begin to lose some efficiency etc. But realize you will be saving money on the trans, adapters, etc.

But the cool factor of the 4bt= priceless.

 

[Lonesome7.3]

That is one thing that gets me. The cost of the conversion versus the cost of freshining up the 318.

 

[pennsylvaniabo]

sounds like me and deciding if i wanna go DRW or not

 

[Lonesome7.3]

I had a hard time with that one once a while back.

 

[forcefed]

4bt. Cost for conversion might be costly but the reliability and mpg will make up for that.

 

[Darrin Tosh]

4bt. Cost for conversion might be costly but the reliability and mpg will make up for that.

,..And don't forget the Coolness Factor!,..

 

[Clydesdale]

And one more big clumbsy truck with a 4 popper might be the convincng I need to head that route.

 

[Black dawg]

awhile back I worked on a 77ish ford crewcab on 35s. It had a p-pumped 4bt and 5 speed out of a fed ex truck. I was surprised with the power out put even with a mild plate and no afc tuning. he said its averaging 25mpg.

 

[Lonesome7.3]

The cost of what I have planned for the 318 is almost as much as the 4BT would cost to drop in. So eather way I will be spending soem money. it almost seems like the question doe snot even have to be asked. The one issue I will have no matter what is the fact that I will be changing my grandfather's truck.

 

[crashnzuk]

I would say go for it. I doubt grandpa would look ill upon you for making his truck more fuel efficient and every bit as reliable as the trusty ol' 318. You will want to swap the rear axle to at least 3.54s, but you may have that covered with your donor truck?
Travis..

 

[Lonesome7.3]

I think the donor truck has even lower gears. A gear change is not something I planned on. That I may have to look into a bit further. I wonder if I can locate some willing to trade.

 

[crashnzuk]

If your donor was an early non-intercooled 1st gen with an auto (727), it will most likely have 3.07 gears. If it was any year with a 5 spd manual or an overdrive auto, most likely 3.54s, but there are trucks out there with 4.10s.
Travis..

 

[Lonesome7.3]

The 72 I have has 4:10's already. The donor truck is an older military truck with super low gearing. I do nto know what is in it but I htink top speed is 15 mph with the governer off.