[digitalsh4man]

I've been contemplating this project for years and I finally have kicked it off. I bought a fully running RC so I can drive it until I'm ready for the swap. I'd like to get your input on a good doner truck model/year. I am already sold that a 6bt Cummins is the engine to get. I'd like the resulting RC to be computer-free, totally mechanical. What is the best tranny for rugged/farm use (not extreme offroad). Should I go with a Dodge that mates to the 6bt? What about an Allison? Thanks!

 

[Canadian country boy]

Welcome. Ramcharger's are tough machine's with tough engine's from the slant 6 all the way to the Cummins. The 3 speed A727 is strong and reliable and so is its successor the A518/RH46. Doner trucks from '81 - '93 basically.

 

[RXT]

There really is no ”Best year”, it’s really gonna come down to best find, or best deal. Ideally, and 89 to 92 will be the most direct fit since the chassis they come in are the most similar to the RC. Additionally, a 4wd donor will also come with the most correct front axle and a matching right drop transfer case. The main downside with a donor in those model years are possible lack of an intercooler, 727 transmission, VE injector pump H1C turbo And Dana 61 front axle. Keep in mind that those components can be replaced or modified but it will add cost that may not exist with other model years. As you get into later model trucks, you get more powerful and more desirable versions of this engine (2nd gen engine in particular) and better transmissions, but you can’t take advantage of their transfer case or front axle because Chrysler made big changes there that make them incompatible with the older trucks. 3rd gen Cummins engines began to use computer controlled VP44 injector pumps. It’s simple enough to still be a good candidate for a swap but that particular ip was not very reliable. After that, you start getting into computer controlled engines but this is also the start of the 24 engines. All engines share the same architecture and therefore can be mixed and matched in almost unlimited ways. Want a first gen engine with a 24 valve head, it’s possible. Want to decomputerize a 6.7? It can be done. So, in general anything is possible if you have the bank account.

You brought up transmissions. It’s possible to install almost any big truck transmission, including big rig transmission. An Allison behind a Cummins Isn’t out of the ordinary. It’s done a lot in commercial trucks, and speaking of which, your donor doesn’t have to be a Dodge Truck. Many commercial trucks, school buses and construction equipment came with these engines. Some will require more adapting to work, but the Cummins were designed to be universal. There also 3 cylinder versions and 4 cylinder versions that you might consider too. In fact there is a propane version which uses spark plugs and a distributor.

One last thing, there will be a potential added cost in terms of supporting mods. The 6BT is heavy and torque output exceeds every other engine you could find in a RC/W150. Highly recommended is a one ton front and rear axles

it all depends on what you want, what you can find and what you can pay

Ed

 

[digitalsh4man]

Wow, thanks so much for all that data Ed. That's what I was looking for and more. I think a 6bt with a 1 ton suspension is what I'm looking to do, completely non-computerized.

 

[u2slow]

Best to me is any 5spd 89-93 with the cummins. They are either 3.54 (most common) or 4.10 ratio axles. Always a Dana 60 front and 70 rear; 8-lug.

Choose intercooled or not... but be prepared to swap the rad, rad support, and clutch pedal from the donor truck. It will take a little wiring customizing to delete the PCM; or adapt the existing wiring for the diesel.

The newer 5-6speed allisons need a computer.

 

[DODGEBOYS]

l,d get a 1989 to 1993 dodge truck with the 6BT and 618 dodge tranny an t-case that way you get everything to do the swap = dodge to dodge [ piece meal projects are the ones you see on the side of the road for sale ]

 

[DarrellLicht]

are you set on running an auto trans?

If so, there are ways to making them hold up better. upgraded flywheel, input shaft, deep sump pan, auxilary cooler. As long as you don't run in excess of 375hp, I would think any auto trans the donor truck came with will do the job. and 375hp is pretty attainable with minimal engine mods and is plenty of scoot for a little ramcharger.

But if it were me, I would hunt for a 94-97 12valve with the NV4500. To which you will be hunting for a long time for one of those that can be parted out.

a 89 to 93 with the getrag 5 speed will do the job. But I hear conflicting info on the durability on the Getrag 5 speed they typically come with.

I don't think i'm pushing 300hp on my cummins ramcharger, it goes like a scalded dog, and i'm always scared of breaking something.

What have you budgeted for this project?