There's a few different mounting options but if you have a 73 and later super beetle you need to do some fab work. Some mounting kits put the shifter above the tunnel which forces you have to cut the body and use an adapter on the shift rod. There are also 10* mounting kits that tilt the nose of the tranny down 10* to go through the existing hole but this also tilts the motor 10* and can cause other problems. The last option is the berg nose cone adapter which allows you to put a beetle nose cone on the bus tranny and use the stock front mount. The berg setup is one of the easiest but most expensive.
There's also the issue of bell housings and starters. If you go with a 002 tranny you can use a beetle starter or a 002 starter (bosch SR17) and since it's a shorter bell housing it won't push the motor back.
If you're using an 091 tranny the bell housing is 1/2" longer and a number of things are different. You need to use the type 4 lower engine studs in the block since they are longer to reach through the bell housing. Same thing for the half-moon bolt that goes through the starter and speaking of starter, you can only use the late bus (76-up) starter ($$$ for a bosch SR87). Even after that is done you may still have problems with the tins since it's 1/2" back.
The other option with the 091 tranny is to trim 1/2" off the input shaft and bevel it down again. Then switch to a 002 bell housing to use a type 1 or early bus starter. The motor with end up in the stock location and you won't have to switch any studs or bolts. Best of all the 091 was a fair bit stronger than the 002 so you get the best of both worlds.
Just a little help from someone who's been there
