13b 5 speed
 

i have the opportunity to buy a 13b rx4 5 speed box. flywheel and clutch not included.

ill buy a 12a turbo 5 speed or 12a single dizzy motor shortly. i wonder, will they bolt up? what mods would need to be done?

regards

The tranny will bolt to the engine without any issues. Whether it will work in whatever chassis you're putting it into is a different question.