Best transfer case for a Flat fender

Any advantage to a Dana 300 transfercase over an NP205? I have the NP 205. Should I go to the trouble of locating a Dana 300 and adapter plate to go with my SM465 tranny? Thanks Todd

 

The D300 some advantages.
1. it's smaller and actually fits without a very large hammer. OK, it's been done but the the 205 is BIG.

2. D300 has lower gears, the 205 is ~2:1 lower range and the D300 is ~2.6.

3. Twin stick conversion, for front, rear or 4wd. Not sure about the 205 but it's an easy mod on the D300.

 

A NP205 will be huge for a flat fender. The frame rails are much closer together in a flatty than in the pickups the NP205 was used in. Plus I think it will stick down too far. And it does not have a very good low range: 1.96:1.

A Dana 18 will give you a better driveline angle than the Dana 20 or Dana 30. Why change?

 

The only advantage I can see with a twinstick is 2 low... But I agree, Dana 18 can take some cajones going to it and be fine. I wouldn't worry too much about using one behind a small v8

 

I got a Dana 44 rear which has a centered rear. I need a transfercase which gives it a straight shot to the rear end. Thanks todd

 

then a 300 is a no brainer, straight shot, good low range etc etc.

 

I would have stayed with the 18 and off setaxle. The 18 is relatively light but will stand even more than a small V8 in a flatty. I have been runing one behind a 381 sbc since 1982 with out any problems. It got a set of Terra Lows when they came out (10 years back?) and I am using a case from a 20 which is large hole and has a bit more beef than the small hole 18's. I am a bit opinionated, but I think the 18 was one of the most over-built components ever for its original application.

 

jp magazine named the dana 18 as the best transfer case ever. I think they said it could handle 400hp or so

 

400 hp? I would never have thought that.

 

If the SM420 has the factory adapter to a 205, check that the combo is not too long for your wheelbase. A long trans-TC adapter is common for pickups, and will not work well in a CJ. Substituting a D300 for the 205 would not correct this problem.

 

I would not run the sm465. Don't run anything that requires you to have an adapter.

 

There are no 4 speeds that will bolt a to a dana 18/20 or 300 for the most part without an adapter. The adapter for the sm465 to dana 18/20 is only 1" thick, not bad at all.

 

I can attest to the D18 not handling a V8 very well, I personally stripped the teeth off 2 bull gears with my 360 that was in my 2A. A 300 will be a much better choice than a 205.

 

I am running a T18 with a dana 20 with Tera Low gears in my Flatfender 2A. I also have a centered Dana 44 from a Commando. I love the low noise level with the top on, using the dana 20.

 

Sounds like a tough /durable combination but......

I opt for either the large hole or the small hole model 18 with 1-1/4" intermediate shaft.
3-1/8" small hole or 4" large hole selection dependant upon transmission/adapter input.
They are common.
This is one tough little gear drive unit. Not chain driven; like some units.
The standard flatfender jeep uses the desirable twin stick version.
Unlike the 20 or the 300 the model 18 is a drop down style of transfer case.
This lowers your TC output by about 4" which lowers stress on the universals.
The offset locates the front and rear axle carriers in line.
That means you don't have to multitrac around prominent rock outcrops.
The standard 2.46 gear reduction is good for most conditions.
If you want to build it to the extreme consider installing the model 18 offset components onto a model 20 case with Terra low.

 

These little units are starting to show some age however. I have had the "fortune" of finding 3 different 18s with broken cases in the past couple months. All were 1 1/4" shaft cases. One big hole and two little holes. There currently isn't another cheap option but to keep rebuilding them. None of the 3 were behind any horsepower or were driven by crazy drivers and all three had good torque side mounts. As I said they are beginning to show age.

 

I can attest to this. It generally takes 3-5 cores to put one good 18 transfer case together to make a saleable unit. Sometimes you get lucking and only one or two gears may need replacing but more and more frequently it takes much more. Output shafts being worn out, cases with damage, etc.
I still run the 18 in most of my CJ's and will continue to do so as it is a good unit, but 400hp? Not realistic unless strictly in super low traction situations.