196 T18 Trans Dana 18 vs Dana 20 t-case

vmaxmike

New member
I'm looking for some advice from the knowledge base here please. I'm at the point that in need to make a final decisions on what combination I'm going to use in my '62 80 series. Below is the back ground....

The engine is going to be the 196 4 cylinder I finally located one with the correct t18 4 speed from an 800 that is currently bolted up to a factory twin stick Dana 20 transfer case. I've got a 196 t90 Dana 18 currently in the chassis that I was going to use until I found the 4 speed. Front axle is a closed knuckle d30 with Scout II disc brakes, and I have both a centered d44 as well as a tapered axle offset d44 for the rear axle. The gear ratio in my axles is 3.73 and I plan to stay on close to stock height tires and SUA. I've got the manual throw out linkage as well as a complete firewall to graft into my tub for the necessary clearances to use this vs. Hydraulic set up. So it this point I have all the pieces to go any direction I just need to make a couple final decisions and I'm hoping someone has been down this road and can offer some insight. This Scout is going to be a daily driver and will probably get a 6 1/2' snow plow. Not going to be rock climbing just want to have decent power and ability to cruse highway speeds comfortably.

Ok first is Dana 20 or Dana 18? I understand the upside of the d18 is a lower gear set, but I think that's it? The Dana 20 is stronger, quieter, and has more shift combinations as it allows high or low range, 4wd, rwd, or fwd independently. The d18 would allow for an overdrive but with 3.73 gears I don't think I'm going to need it..? The d18 I have is a later "big hole" so I could swap the gear set , I'm trying to decide if it's worth the effort required to do so. Thoughts or experiences?

Next is manual vs hydraulic throw-out on the clutch. I have the pieces and ability to change firewalls as the tub is stripped bare and off the chassis currently. I can convert it over to the manual that the t18 was set up for. My question here is I've seen where someone has modified a manual throw-out bell housing to have a hydraulic slave cylinder (see pic) it seems like a lot less work to do this than change the firewall and a little body lift would allow the needed room for the valve cover. So again thoughts or experiences?

Last is gear ratio is/has anyone run a 196 t18 with 3.73 gears that can offer some input? I'm thinking it's a good compromise between power and ability to cruse highway speeds.


Thanks in advance.
 

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I would install a Dana 20 for the fact it is a lot quieter than a 18. The Scout II rear axle is also easier to get parts for.

Unless you are doing front digs (where the 20 would be an advantage), the 18/20 shifters can be modified to do most of the same things.

I did hydraulic linkage on mine with a mount off the top of the bellhousing and a removable cover on the firewall to allow clearance. It was fairly simple fab work with the engine and trans assembled on the ground.

3.73's with stock tires shouldn't be too bad. A little sluggish up some hills maybe but better on the flat. Hope this helps some.
 
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