New Zealand Datsun Club

Does anyone know if a gearbox off a a15 will bolt straight onto a a12 in a 74 120y coupe? Cheers.

YES!
So long as it's a floor change box.
Most of the C20 Van boxes were column shift, and wont work in a car body.

The rear mount is located further back on the 5 speeds I think so you would probably need to engineer a new mount. Also the reverse switch can also foul the mount bracket on the body.

I am looking at an a15 4 speed to replace my a12 4 speed. I noticed there was 2 mounting points underneath the car for a longer gearbox. The a15 box looks heaps different and there is a plug with wires coming out of it about an inch or 2 from the gear stick on the a15 one that the a12 one doesn't have.

A proper a15 gearbox will be a 60 series. They have a 60 cast on the side.
they're a bit longer, so as Vaughan said there might be some fabrication required to the Xmember.
I can speak about the reversing light switch as I've never done much to a 120Y, but on 1200 the rev light switch hit the tunnel.
I think the other one might be a "cruise lean out" switch or something like that.

I have an a15 and 5 speed box in my 120y coupe (75') and had no issued with the reverse switch (my car is auto orignally so not sure it they are different). Just had to make up a new gbox cross member.

Ok thanks guys