1972 Commando Halfcab build...

It's definitely a T18 or T98; if you look at the pics below you'll see the SM420 (pic on the right) squares off where the shifter housing meets the case but the others do not - the one I have does not square off. The one I have also has that little tin cap on the top of the shifter housing.

According to Novak the T98 was available as a special order in Jeeps until 1972 and it's pretty rare so I'm guessing it's the T18. Also according to Novak the pre '76 T18's were close ratio and had a first gear ratio of 4.02 anything after '76 would have the 6.32 1st gear, '76 is the crossover year and you may get one or the other. I'm guessing it's pre '76 since the 225 was not used after '71.

 

Never know what you will find when you lift the hood...

You know if that was my project,, congrats by the way.

Your son must be going through the roof.
My Dad would have been my all time hero after that.

Anyway.
You have a sm 420 in there. So I would with out hesatation build up or buy a Small block chevy for it.
Beings you have the room for it and it would bolt right up to your tranny.

If your sons reading this cover his eyes.

I would think about something like a 327 with a small carb. and HEI.
keep it from being a dangerous hotrod but be very reliable and very trail worthy.

This way he can brag but not kill himself.

He get's some time and maturity under his belt and if he keeps it,
he could build any SBC he wants later and drop it right in.

A 305 with TBI out of wrecked truck or say a camaro would work too.

Keep in mind chevy's run cooler, and parts are cheap and plentyful when broke down in the middle of no where.

You can run street gears in the axle's with that sm 420 and still crawl around.

So you should be able to keep what you got for axles just inspect them for now.

Just keep it simple for him.

My kids first cars where very cool but low power good brakes and as reliable as possible.

And I fixed my daughters gas tank float to read off a bit she never had to call for being out of gas.

She had a cherry 66 mustang very good memories and nobody got hurt.

By the way your son will be nagging about getting to work on it..
He may not have wrenching skills yet but.
Go buy a bunch of sandpaper and let him at it.

PS
Look at the cover on the side of your tranny very positive tip off for a SM420 ALso the bulge to right of the cover looks like A sm420.
But the ears where the bolts are look more like a 465. But the 465 has ribs and different bulge. I am almost certain that it is a Chevy tranny...

Need to see alittle more of it to 100 percent sure.
It has an adaptor in front of it. Looks like a short adapter to the Tcase..

People will bolt anything together so nothing is really a suprise.

 

And the plot thickens...the adapter clearly says T-86 and Chevy on it - not sure what else it says (I have more pics to post but I've got to get out of town!). The shift pattern is standard H with Reverse being to the right and up which would indicate an early T18 (late T18's are to the right and back) and it virtually eliminates an SM420 (in the brief research I've done it appears the SM420 shift pattern is standard H with reverse being left and back). It does have the access panel like the SM420 but the SM420's panel is more in the middle of the tranny where any pics of a T18 I've seen have it towards the front of the tranny with a hump (similar to mine) in the rear. From the picture below I'm 99% sure it's a T18 because the passenger sides are nearly identical - I would say a perfect match but mine's way to dirty to get a real good look at it.



On a side note: Novak's picture of the T18 does not have an access panel but I found the picture below at http://www.jeeptech.com/



And the axles (D44/D30) have 4.27 gears (according to the plates that are still on the cover) and according to JP Magazine they only came with the Hurricane/3spd combo...could you even get the Hurricane in '72...

I've got to get out of town so I'll let you all think that stuff over for a few hours...

Also - it will be getting a small block Chevy for the exact reason's mentioned - plentiful and cheap!

Thanks to everyone for your help by the way...

 

I wouldn't really trust JP knowing much about Jeepsters and Commandos, but that's just me and a whole bunch of other peoples opinion . The Bullnose was never available with a 4 banger. But I digress. The T-18 was available but only with the 232 which would also explain the 4:27 gears. I've only ever seen one with a 232/T-18 combo. Maybe I should go see if the guy still has it.
Almost forgot, Chili, get outta town, but hurry back.

 

sm420 is left and down i have one and i dont think that its what you have. a good way is to look at the passenger side of the tranny an 420 will have a large buldge.

 

That is most likely a t18 but, it could be a t98, both had cases with that bulge in it for reverse gear right behind the PTO cover. It is most definitely not an SM420. The SM420 only has the top 2 bell housing bolts accessible from the outside of the tranny, the bottom 2 thread into the tranny itself from the inside of the bell housing. You can see some pics of this in the 420 swap article from the tech library.

 

Cool, thanks for the info. Apparently the best way to tell a T98 from a T18 is to open the top and count some teeth (don't remember the specifics right now) but I won't be able to get to it for about two more weeks...

And at least someone left a can of engine degreaser in the Jeep so I can get that started...

 

I sold this Commando about 6 months ago to a good home in Colorado.

I lost my phone so I don't have the guys number anymore to see how it's doing!