Well I need to make a frame to hold the engine and to hold the diff and to mount to the car so with a mx5 rear subframe I have good handling easy to adjust suspension , disc brakes , diff and drive shafts (diff will be gutted and chain driven ) so by making a stand alone unit that has all the above built on one frame it's just a case of bolting to the car .
I might end up just using the existing mx5 subframe as a jig and make a box section version ??
There will be plenty of cutting machining and welding what ever happens