transmission conversion
 

OK, maybe it's not a Cummins, but it is a Dodge and it is a diesel.

I'm thinking of replacing a 727 load flight with a transmission from a '92 D250 equipped with a Cummins (would that be a 518?). I don't suppose I'd be lucky enough for it to be a bolt-in, but I'd like some info on just what is involved.

Maybe I should just leave the question at that, because from here on it gets complicated. The chassis is a Dodge M500 (Winnebago motor home). A previous owner installed a Perkins 354 and kept the original transmission. The original engine would have been a 440, so I assume that's the bolt pattern mating the engine and transmission.

He also installed a Gear Vendors remote mounted overdrive in place of the hanger bearing. The overdrive exploded and I'm looking at alternatives to replace it. I really need overdrive because the Perkins is a low speed engine and it doesn't really like to run over about 2500 rpm. That gives me a little less than 50 mph.

Some of the possibilities I'm considering are:

Replace the transmission with a newer one that has overdrive and replace the overdrive with a hanger bearing. I have the transmission. That's why I'm on this site.

Replace the overdrive with a newer GV unit ($1700 exchange plus a few parts I need to make it fit, say 2 grand altogether). Probably the simplest solution but after what happened to the current overdrive, maybe I should be considering something stronger.

Replace the overdrive with something simpler and more rugged such as a small Dana-Spicer auxiliary transmission. The problem is finding one.

Replace the GV unit with one from a Volvo. They're both Laycock type J's. The Volvo version mounts directly on the transmission, so I'd have to use the GV front housing. Fortunately, it bolts up to the Volvo od. I'd have to have a new input shaft machined. I'd also have to make up an adaptor for the output since the Volvo has a flange and the GV has a slip yoke. I have the Volvo od.

Maybe the ultimate solution would be to transplant the Cummins and its tranny as a package. That way I'd have a combination I know works, and I already have the engine, too. Engine swaps always involve a lot of details that weren't apparent before I start, and I'm afraid this route could take a lot longer than I plan. Also the Cummins has a lot more miles on it than the Perkins.