Has anyone used a s12 box in their 1200 ute ?

I have a 71b s12 box and am planning on using it for my ca18 conversion in my ute with the Maddat kit .... I was told it would fit with no trans mods ?

Yes, the CA20 gearbox fits thr CA18 engine but its not a good fit in a 1200. The shifter will be back about 3 inches so cut the floor.

Sweet thanks !! So it's similar to fitting the standard ca18det box then ? The ca18 box is 4inches back from the stock hole ..

are the s12 Box a better box to use compared to a stumpy box ?

The stumpy box lines up in the 1200 perfectly.

With any 71-series gearbox it is a tight fit and some hammering & cutting is required. Some 1200s came a 71-series tunnel, coupes & sedans.

In your opinion do you think it's worth cutting and beating the trans tunnel up to fit the 71 series box ? Or use a stumpy box ? I have read that the stumpy is a hard shifter at high rpm ...

S12 and stumpy boxes are getting very thin on the ground if you need to replace one. Ca would be easiest to source but you might even be able to then use rb box with the ca bell housing I think. Or is that for Sr?

Interesting ! I never though about an Rb box ..... Basically I'm trying to get away minimal trans tunnel modification ....

The Rb box would be bigger box compared to the stumpy box ? I would have to Do a tunnel change ?

RB engines were mated to different gearboxes
* FS5W71C - same as the S13/S14 Silvia gearbox, except with RB bolt pattern
* FS5R30A - RB26, RB25DET and Skyline 4WD applications, stronger and heavier

71C gearbox for RB20 can be used with other engines (e.g. CA18DE, KA24DE, SR20DE, VG30) by partially disassembling the gearbox and swapping the front half of the case it can be used on the other engine.

If you can find the 1200 tunnel from a 71-series automatic (L3N71B), it will go into the ute and you can still use the heater. You don't need to change the tunnel, but it makes gearbox installation easier.

Mmm it's looking like I'm going to have to some trans mods !! I'll try an hunt down an auto tunnel and fit a standard ca18det box !

Or just put up with a crunching stumpy box lol !

ive used a stumpy in mine. It came on the l20b that was in my ute when i purchased it. I thought it would be the "easy" route.
Had to change to ca bellhousing and also change one of the bearings. No drama there. Just a little research on what bearing to use etc etc
I also went this way as i thought it would save me some time and $$ in tunnel mods as i cant weld and i outsource this.
All well and good getting the engine in the car with the gearbox attached. Gear stick lines up perfect.
But......cannot remove/service gearbox without engine out or cutting hole in firewall to back the bellhousing bolts out. I've also had trouble with a speedo corrector box to fit next to my gearbox crossmember.