the trans is no problem, it will bolt straight up
the cam on yhe other hand could give you fits
on the A12, the oil pump and the distributor are driven by the same gear, at the front of the camshaft, with the fuel pump mounted aproximatly centered between no.2 and no.3 cylinders
on the A12A A13, A14,and the A15 the distributor is mounted about centered between no.2 and no.3 cylinders (about the same place as where the A12 fuel pump would be) that would leave you with no way to drive the distributor.
IF I remember correctly, you can put a cam from a later one(A12A,A13,A14, A15) as long as you have an electric fuel pump, but putting an A12 cam into the other ones will require an alternitive ignition system

The way to tell if the cam will fit from the A12 to the A15 is to compare where the distributor and fuel pumps are located. If both distributors and both pumps are located in the same place, the cam will fit. I would like to find a crank fire ignition for mine so I can use the old A12 Crane cam in an A15 or A15, it is hot.

mareo

Although others could tell you better, I'm pretty sure the A12 cam doesn't fit in the bigger engines. Something to do with where the distributor drive gear is located?

Just a quick note. You might find some of the info you need in the main forum under"stupid question" topic. I had a similiar question about transmissions, and dimlight and some of the guys really hooked me up. Hope this helps.

roughneck

hey fellas
just a quick little coupla questions here for ya. i am putting an A15 motor in my 1200 coupe, i have a sunny 5 spd already in at the moment, will i have any difficulty installing the A15 to this g'box? i also have extractors will it hook up to these alright? my current A12 has a lumpy cam, could i install this cam straight into the A15?
im will end up supercharghing the A15 but what mods should i do first? carbs? port and polish? etc.
also what diff will fit straight into the 1200 housing, that is stronger??
thanks heaps for any advice given.