Travco 270 getting a Cummins Diesel swap

jeeprobb · Unread post by **jeeprobb** » Sun Sep 15, 2013 1:19 pm

Hi all. Well we finally found a 270 it is a 1973 two plus two and we have been busy camping with it. No name yet but the wheels are turning, the favorite with my wife and daughter is "Aunt Fanny"! I have found a Cummins and Allison tranny to do my conversion this winter and am trying to uncover as many of the problems before I get started. Has anyone had any experience with changing axle gears? I am trying to find out if any Dana 70 gears will work or if the axles used in our units had a different offset. Any thoughts would be appreciated. If folks are interested I will try to post pics as I go through the conversion. So far the Travco has exceeded our expectations and we are planning a western U.S. trip for July 2014, assuming the swap goes as planned:)

jeeprobb · Unread post by **jeeprobb** » Sun Sep 15, 2013 1:29 pm

I almost forgot, the P.O. had a double mattress custom made for across the rear of this unit, when I say custom made it was made with the curve that fits the rear of the Travco. It was not used much if any and is still in the original shipping bag. We have already put in a queen size bed and would like to sell the double. If any one is interested let me know, they claimed to have paid $800.00 for it but we would consider an offer. Thanks Robb

Unread post by **Acesneights** » Sun Sep 15, 2013 4:47 pm

Very Cool.\nAFAIK The Dana 70 is the same as any other. Now ring gear spacing may or may not be an issue. IIRC on some diff's you need a spacer. I know I went form 4.10's to 5.13's on my old 77 F250 with a D60 and had no issue. I would talk with a gear shop or manufacturer like Zoom or Richmond.\nDefinitey keep us posted with LOTs of pics. My 440 isn't very healthy. Making some weird noises and getting tired. A Cummins swap is next for me as well but I think I may just go with a Dodge OD tranny for sake of ease. Allison is a nice unit. Not sure if any or what one would be available with like .7 or .8:1 final.\nI forget what an NV4500 ran but around that ration I would think would knock down that 4.56 and like you said if you got a Cummins pulling it could probably run 4.10's

jeeprobb · Unread post by **jeeprobb** » Sun Sep 15, 2013 7:14 pm

I forgot to mention that the Allison is old school. No overdrive just a straight 4 speed with a 4:1 first gear, it is the AT545 used in many many school buses, med. duty trucks, and the like. I want this rig to be cave man simple with no computers and minimal wiring. I am looking at 3.07 gears which would net me about 1900 RPM at 60 MPH with the tires that I'm running. My 440 is a great runner and strong but as you may have guessed very thirsty. I have had five Cummins Dodges and love the crazy torque and ease of tweaking the early 12 valves. I am hoping for around 12-14 MPG with the Cummins and that will more than double what I'm currently getting. Time will tell. Robb

Unread post by **Acesneights** » Sun Sep 15, 2013 8:17 pm

jeeprobb · Unread post by **jeeprobb** » Mon Sep 16, 2013 6:25 am

Hey Acesneights. I don't have any practical experience with running the Dodge OD in one of these but several local tranny guys I have talked to all thought the weight/heat might be too much for the Dodge tranny. That is why I decided to go Allison. Just some food for thought, again I am no expert!

Unread post by **Acesneights** » Mon Sep 16, 2013 5:15 pm

I forget the number but the Dodge OD tranny that came behind the 1st gen 12v wasn't the best but a 47RH I think can be used with a stand alone and built to withstand some pretty good abuse. Nothing wrong with the Allison at ll. It is one tough unit. I just want OD when I do mine. You could also use a bread truck adapter from the 4bt and run a GM 4l80 which might be better. That will also require a standalone controller.

jeeprobb · Unread post by **jeeprobb** » Mon Sep 16, 2013 8:01 pm

Yeah I thought about both of those options but am pretty much anti-computer when it comes to vehicles

...I don't know what I am going to do when all of the old stuff rots away!

Unread post by **Acesneights** » Mon Sep 16, 2013 9:06 pm

\nPreachin to the choir...I own an 86 M1008. No electronics. In fact most of my stuff right down to my two Cub Cadets are 70's-80's vintage.

jeeprobb · Unread post by **jeeprobb** » Sun Oct 06, 2013 6:48 am

Hey Aces and eights, I have started my Cummins swap and am ready to start posting about it. Should I post here or under engines, don't know if it matters but I thought I would ask. Trying to keep things in order

Thanks Robb