d300 4x4 conversion (1969)
 

First time post .......so.......dont beat me up too bad. My latest project is a 1969 d300 dually cab-n-chassis...138" wheelbase. I am going to build a "camper" out of this behemoth, using the original 318/thermoquad/a727 combo. I purchased this from the original owner last year and it has 52k VERIFIED ORIGINAL miles, used only during harvest season as a crew support vehicle . My mission is to convert this beast to a 4x4(er 6x6). Thankfully, the front axle is already the old-school straight axle, so my thoughts are as follows. Adapt a dana 60 dually ft axle assy....and hopefully...get a trans/transfercase setup from a later-model mopar truck. Ft driveline would likely have to be custom-built, but, no big deal there. Since this truck was born in a non-computer age era....the trans/tcase unit will have to be compatable with my prehistoric system....meaning, no computer assisted trans interfaceing stuff. Would a 1980's full-grown dodge truck 4x4 trans and tcase unit be a possible "bolt-in" solution??? I am dealing with a generic 318 block bolt-up/etc. ANY input would be greatly appreciated....thanks.bob

I think you're on the right track with a later truck as a donner, being a small block you can consider an overdrive transmission. You could get trans, transfer case, drive shaft and front axle from the same truck.

That 318 might need some hardened valve seats and a stroker kit. :)

Iowan thanks
 

thanks guy.... After I get this all wheel drive thing operational, I am considering a set of "modern" aluminum heads, so I wont have to deal with some of the seat issues as you point out. Ive already had to get rid replace the thermoquad accelerator pump plunger orings with viton so our CRAPPY alcohol fuel mix cant eat it(as it developed an accelerator stumble due to deterioration of sOEM seals). Would, say, a 1988 ish dodge 4x4 trans bolt up?....what "bolt=up years COULD offer an overdrive?. This is a heavy pig, and will never get over about 10mpg with the 4:10 dana 70hd rear axle , BUT....I have a fantasy of it getting about 12mpg on flat ground....we'll see