SM420 or T90/ Dana 18 or Dana 300

I have a Dana 44 offset in the rear. Dauntless 225. and Have reached a dilemma. I just bought a SM420 which mounts to the dauntless, I also have a friend that's giving me a Dana 300. I will have to run a adapter to run that. I just found a Dana18 paired with a T90 for sale. (Don't know a price yet). I also already purchased a ford nine inch but is too long and need to be cut down.

The question 1. Which setup would yall run. I feel the SM420 with dana 300 and ford nine inch would be a strong setup. But then again the dana 18 is setup to run with my existing setup easily and i wouldn't have to cut the nine inch. I could also keep the sm420 and ask him to separate the D18. The three speed and 18 would be a more original setup too.

Question 3. Will the t90 mount to the dauntless without adapter?

Question 2. What would be a good price to offer for the Dana 18/T90? or just the D18?

Thanks!

Check out my build for more info on my setup.
http://jamco6000.blogspot.com/

 

Without knowing what you want to do with the Jeep when you are done, it's rather difficult to give you any real advice. Many people run the SM420 with a D18 and the offset rear axle. Most t90 to Dauntless run an adapter to the bellhousing. I think in the last year or so of production the bell was changed to eliminate the adapter. You are correct about the SM420, D300 and Ford nine inch being a great setup but it would seem kinda overkill to then run the stock D27 in the front. Again, what you ultimately want to use the Jeep for would indicate the best way to go. If I were going to use a Ford 9" I'd leave it full width and then use a matching D44 in the front and skip cutting down the Ford axle.

 

It is going to be offroaded, building up for my Dad as he always wanted one so I wanted to keep the stock look. I am going to run a SOA with stock YJ with 33's. The Dana 44/30 will be plently enough for me. Any advice on a good price for the t case?

 

18 tc are everywhere. They can be had for $50 for an original 60 yo unit that could use a rebuild all the way up to one rebuilt from a good shop for $800. Price an adapter from the 420 to 300 and that may be the deciding factor for you. Most 420s need a rebuild and are over 5o years old now. So with an adapter, a 420 rebuild and put together you could easily be a grand there.

 

Any way you go, you're gonna need an adapter. The T90 requires an adapter to bolt to the v6 (and it needs to be the long input shaft T90). You can usually find one of these adapters for cheap on the used market. The 420 trans will bolt to your engine, but will require an expensive adapter for either transfer case. These are rare to find secondhand.

 

I'd consider going with a wider pair of axles if you are going to do SOA with stock YJ springs. So going with a center rear output t-case would be better for the 9". The d18 has the option to add an all range overdrive which is a pretty darn neat thing to have. There are full width rear axles that are offset which works well with the d18 tcase if you decide to go with the d18 and full width.

 

Thanks for the input. I bought the d18 today. 150 for a rebuilt d18. Insides look gorgeous. Was planning on doin soa with yj springs for the ride and the kit comes with all new spring mounts which I will need anyway. I hear the sua lifts are extremely stiff

Oh and he has an overdrive too

 

Just did some research on the Holbrook's springs and I think I'm sold. 900 is a bit pricy tho

 

If you got an overdrive with that you stole it!!! Get the adapter and go sm420, that is an excellent combo! You have to decide what you want to do with the Jeep, I have 32's and about 3" of lift and love the combo. I can crawl over almost everything. add a dana30 , 44 with full floater conversion, selectable lockers both end it would be amazing. Build it that way first, use it and see how much you like it. Read JP etc. and you see the high lift fad is changing, and spring over is almost gone, really hard to do it right it also adds axle wrap problems etc. You wont look stock at all either and will want to go wider on the axles to keep it stable.

 

To add to what has been said, by the time you invest in fixing steering issues, spring wrap issues, etc., etc. with the spring over $900 isn't as bad as you'd think. Especially for the ride and flexibility you get with the Holbrooks. I've driven a prototype set, had a set on the front of the Race Jeep, and have a set waiting to go on the new frame for the '59-5.

 

:iagree: I have $700 into just the steering for a SOA.

 

Well just finished getting everything off the frame today. So I'm a ways from the suspension. And looks like I'll be going Holbrook. Thanks for the input.