Old Freightliner Expertise Needed...

Looking for some advise from the old timer mechanics. Or some advice on where to pose my questions.

I want to put together a horse hauler, play truck this summer. Not for work, just play. Not shiny and high tech but an old mechanical beast I can spend my weekends working on and tote my camper, GN horse trailer, GN flatbed, or whatever around. Realistically it will be driven less than 10k miles a year and the heaviest it would be hauling would be my buddy's 40' GN flatbed with 25 round bales on it or some tractors. Yes, for now everything it will haul can be hauled by my F-350, but again, looking for a fun project. I've been a gear head my whole life, worked on cars, light trucks, farm equipment, etc since I was young so I'm not new to modifying just never done it on HDT's. Yes I have my CDL, yes I am a truck driver by trade, yes I talked to my insurance company (it can be insured but would have to decide on RV or Farm), yes I know it will get 6-10 mpg (my current dually gets 8 lol, love the V10), yes I understand no matter how much or little money I spend on it I'll never get it back (half the fun of a hobby ain't it).

Let me lay out my plan and questions. Want to start with a 1976-1984 Freightliner Conventional, 36"-48" sleeper, 855 BC Cummins, HT740 Allison, 23k single rear axle w/ air ride, 11R22.5 tires on Aluminum (cruising RPM @ 60 about 1,650 RPMs), modern air ride seats, etc (the rest of the details are trivial to anyone other than me, lol).

*What is needed to swap out what will probably be a 10-18 sp for an HT740?
*What is the frame width on one of these era trucks compared to a '90's FL80 (which is probably what I would end up taking the rear axle and suspension out of)?
*Would it make more sense financially to take out the front-rear and use the rear-rear and buy the parts to make it an air ride or would it be better to take off the whole tandem setup and use it as a "trade in" on the single air ride rear?
*Can power steering be readily converted on these trucks (add a pump and different gearbox) or is it a heavy fabrication custom one off deal with manual steering type of job?
*What would it take to add cruise control? I'm a cruise junky on long hauls and going to visit my daughter in TX from MI it would be nice to have to keep me from flying, lol.
*What other motor options do I have for that era? 6V92TA, ?V71, L10, 3406B, 5.9, 8.3. Gotta be mechanical, gotta make enough power to pull itself down the road if I did load it out to gross (60k ish), no big hills here though. Mostly flatter ground and I don't mind topping it at 45 if I had to on the few bigger ones. Hell, the trucks I drive at work are lucky to top some of them at 50.
*Will the HT740 be strong enough? What can be done to keep it going other than heavy duty cooling and good filters? I know they were popular in busses. What motors did they mate to most commonly?

I know the first question will be why the auto? My wife likes to truck as much as I do and I want her to be able to drive it easily. She's had two shoulder surgeries so shifting is out for her. Although she can drive a manual like most men wish they could before they cut her open. I want the truck to be as light as possible for an antique. Aluminum rims, single axle, small sleeper, only using one fuel tank, etc any other ideas? Top speed is not a concern. If I can cruise at 65 I'm happy. 1:1 is 1:1 whether it's 10 in a direct 10 sp or converter locked in an Ally. I know I'll lose some power and mileage with the Ally but for the limited miles I'll be travelling it'll be fine.

So that's what I'm wondering. I know this isn't everyone's cup of tea but hopefully there are some similarly disturbed individuals out there who can help me out and toss around some ideas with, lol. Or if you guys know of another forum that deals with stuff like this more I'm open to spreading my delirium.

Thanks for reading and hope y'all are having a good weekend.

 

Bummer, I was hoping they had a way to do it. I had an old '84 Chevy that still had working cruise that used vacuum somehow to make it work. Was hoping they had something similar.

Good info on the frame rails. That helps a lot. I looked a lot at the 643 and 653's originally but thought if I ever did hook onto a heavy trailer they wouldn't hold up. That and I think they are SAE #2 pattern I believe that would limit me to the smaller MDT motors, I think.

 

Lol, I know I'm the ####### outlaw amongst my trucker friends. EVERYBODY has Pete's or KW's (mostly in the shop) lol, jk. I just love me some shakers. Started out when I was 16 driving a '75 WFC. I just can't get behind the cab layouts in the Paccar trucks. Although I do rank them second, still ahead of Volvos, Macks and Sterlings, lol.

Something like this with an 855 would be my ideal starting point.

http://montgomery.craigslist.org/cto/4449167468.html

 

That's a good point. I never thought about how the rpms would play nice or not with the trans. I know the old military Shakers used a 250 hp 855 and the 740s. I might pick the brains of one of my camo buddies and see if there was something differant they did. I'd love a 6V92. How is the parts availability for them nowadays? Seems there high rpm desires would match better with the Ally to keep the line pressure up anyhow.