Can anyone tell me some specs on the 420 ? W x L x H , splines , input & output , gear ratios , anything would be helpfull . :usa:

7.05 first
3.57
1.70
1.00
10spline output

If I remeber right the over all length is 10.5 inches..

Dont be fooled they are very big trannys as far as width when you factor in the sm420 buldge..

Heres some pictrues of mine with the novak adapter and with it mounted in the jeep.



http://wheelingpiazzas.com/pictures/misc/24295942.jpg

http://wheelingpiazzas.com/pictures/misc/24522687.jpg

weight: 135lbs

IS that all they weigh?

All I know is there a heavy SOB.. We used a nice little rigging setup to put mine in place.. Of course we put it in and took it out 7 times due to the clutch.

So which transfer case do you have it bolted to with that novak adapter ? And does it weigh that much without the clutch and bell housing ? I know it sounds stupid but what does the sm420 usually bolt up to ? I am guessing it is a chevy product . I am interested in it because it is short in length and has the 7.05 first gear and I am told they are a tough unit .

Thank you to everyone who responded ....:usa:

Originally posted by howiebilt
And does it weigh that much without the clutch and bell housing ? I know it sounds stupid but what does the sm420 usually bolt up to ? I am guessing it is a chevy product . I am interested in it because it is short in length and has the 7.05 first gear and I am told they are a tough unit .



You are correct on all points. The SM420 was made for GM by Muncie. Its super tought, used in trucks up to 2.5 ton. It will bolt up to Chevy engines with a factory adapter. You can get adapters for it to go in front of a bunch of t-cases such as a Dana18, 20, 300, and NP231. Check with Rube, Novak (web page (http://www.novak-adapt.com/catalog/sm420_to.htm) ), and Advanced Adapters.

By the way, have you done a search on this topic? SM420's get talked about a lot around here. In fact there was a good thread just a few days ago about the SM420.


http://www.novak-adapt.com/images/pics/sm420_flq_lr.jpg

Howie,

Someone else here on the board will probably know better than me, but GM used them from the 1940's until the late '60's or early '70's before the 465 was introduced. I also believe there were two versions--2wd and 4wd. I'm fairly certain they had different spline counts on the output shaft? Anyone know for sure??

here you go: http://www.off-road.com/jeep/tech/convtrans/gm/gmsm420id.html

WITHOUT GETTING TOO CRAZY ... I WANT TO MOUNT THE SM420 TO AN EARLY BRONCO DANA 20 .

ANYONE HEARD OF SUCH NONSENSE ???!

THANKS TO EVERYONE WHO REPLIED , IT ALL WAS QUITE HELPFULL .:usa:


HOWIEBILT

Originally posted by howiebilt
WITHOUT GETTING TOO CRAZY ... I WANT TO MOUNT THE SM420 TO AN EARLY BRONCO DANA 20 .

ANYONE HEARD OF SUCH NONSENSE ???!

THANKS TO EVERYONE WHO REPLIED , IT ALL WAS QUITE HELPFULL .:usa:


HOWIEBILT

Sure, check with AA. I dont thing novak does bronco stuff. I've seen it done though.

Pretty much every heavy duty G.M. truck, from 1947-1968, from pickups to bread trucks

MERLE,
I know a guy that has one burried in his garage. Give me a call at work tomorrow.:beer: :usa:

i have mine mated to a toyota dual case. only complaint is they shift clunky. other than that they are rock solid.

I'm having a hell of a time finding a stick for mine... but your right, thats one heavy sucker! Also, you can't clock your transfer case very much if you drop on the passenger side because of the hump on the 420.

Steve:eek:

Originally posted by camo
i have mine mated to a toyota dual case. only complaint is they shift clunky. other than that they are rock solid.

I don't plan on shifting mine too often , I'm putting it between my C4 and the Dana 20 . The Howiebilt Merlin Krawler . Yeah I know I'm crazy ... but I got time and sooner or later you all will catch up or I'll get cured .:beer: :usa:

HOWIE

Originally posted by sjb83cj
I'm having a hell of a time finding a stick for mine... but your right, thats one heavy sucker! Also, you can't clock your transfer case very much if you drop on the passenger side because of the hump on the 420.

Steve:eek:


Steve, I have the lever for mine sitting on the bench. They are a simple design. Why don't you make one? I could get you dimensions and whip up a drawing if you like.

Liveaxle, hey Thanks! If you could do that for me I'll just have to change my opinion on folks out there on the left coast!

That would sure help me alot since I don't have a stick for mine and have no ideal how to fab one.

Thanks again, my e-mail is lucy@cswnet.com

Steve

Originally posted by howiebilt
So which transfer case do you have it bolted to with that novak adapter ? And does it weigh that much without the clutch and bell housing ? I know it sounds stupid but what does the sm420 usually bolt up to ? I am guessing it is a chevy product . I am interested in it because it is short in length and has the 7.05 first gear and I am told they are a tough unit .

Thank you to everyone who responded ....:usa:

I dont know if I am late answering this or not but

The SM420 usually came in 2 wd trucks, If you find a rare 4 wd one it was matted to a divorced transfercase.

On mine Its matted to a D300. which can not be clocked because of the sm420 hump.

And yes it weighs a ton.