you will be making completely custom motor mounts to do a KA, a custom driveshaft, custom wiring harness, IDK WTF you will do about the radiator since the rx7 one mounts so weird, probably wil have to run a rx7 rad. with custom hoses, custom exhaust/downpipe ETC ETC ETC. Sounds like you dont know to much about it so I wouldnt attempt it.