Axle and trans swap ??

[chillman88]

Hey all,

Long story short, I have a 4x4 frame (79) to put under my 86 C20. A buddy of mine has a 71 K20 that has been sitting and I can get it for scrap price.


What would it take to replace the SM465 in my C20 with the TH400 from the 71? I'm asking more about kickdown and dash stuff, I have done the reverse before on my 97 and put in a manual so I have a basic understanding of what I will need.

I'm told the Dana 44 from the 71 should bolt right up to the 4x4 frame I have, can anyone confirm this?

I don't necessarily want an auto but if I can do the swap cheaply I can save up for a 5spd swap down the road.

Unless anyone has an SM465 with a transfer case they want to trade?

Thanks in advance!
--Chris

[Alex V.]

Hate to be that guy but... why? That's a lot of work to get something you may just change back. Even if the SM465 is toast you'd be ahead to rebuild it, and the D44 is a light duty axle.

[andrewmp6]

The front axle will bolt in but both front and rear axles have to have the same gear ratio,Not knowing what you have now and what the dana 44 has i would find out what both axles have before i would swap any axle tho.

[chillman88]

Originally Posted by Alex V.

Hate to be that guy but... why? That's a lot of work to get something you may just change back. Even if the SM465 is toast you'd be ahead to rebuild it, and the D44 is a light duty axle.

No problem, I understand. The short simple answer is because the SM465 is a 2wd and the TH400 is 4wd and basically free after I scrap the rest of the 71.

I understand the gear ratio issue and will be looking into that, but a D44 should be all I need. I'm going to be using the truck for plowing my driveway and firewood gathering, it won't hardly be off-road, that's what my 97 is for. Besides, a junkyard D60 front is about $700-$900 around here, and even more on Craigslist.

[chillman88]

The alternative is I'd be putting the D44 in and keeping the truck 2wd until I can get a 4wd manual. I just figured it'd be nice to have 4x4 working this winter.

[andrewmp6]

Does the 4x4 frame have no running gear on it ?And you can use a dodge dana 60 from a leaf spring truck all you need is these bushings http://offroaddesign.com/catalog/Dod...apBushings.htm

[chillman88]

Originally Posted by andrewmp6

Does the 4x4 frame have no running gear on it ?And you can use a dodge dana 60 from a leaf spring truck all you need is these bushings http://offroaddesign.com/catalog/Dod...apBushings.htm

The frame has the leafs, a 12 bolt rear, rear driveshaft, and the steering gear but that's it. Yes, it's a K10 frame. Only paid $100 for it. I thought I had read a dodge axle would work, haven't had time to check the local u-pull, maybe I can get there Sat...

[andrewmp6]

If you go dana 60 then you will need a matching 1 ton rear axle since the 60 is 8 lug and your 12 bolt is 6 lug.

[chillman88]

I understand all the axle issues. I'll be using the 14 bolt that's in the C20 now until I can build a full floater down the road.