Hey, so I'm thinking of putting a rotary into my 1963 mg roadster. I've looked online and it looks like it's fairly straight forward to swap a Rx7 12a motor, but I haven't found much out about if a Rx7 turbo II 13B would work. I would like to install the 13B because there is one available and it seems like it has more power and better reliability from what I've read. I was wondering if anyone could tell me what the differences in outer dimensions between the two motors/transmissions are in terms of fitting into my car?