its gonna be alot more work than it seems like you are planning for (no offense). on top of that you have a 300sx which i have a pretty good feeling probably weighs more than an rx7 fb and those 12a rotary's are gutless without anything done to them I had a buddy who had an rx7 fb that struggled with power so if you plan on using the rotary in the 300sx expect that
#1984 300sx project advice plz :3
dire vault
if your only using the tranny and driveshaft with the 300sx motor if thats what you mean thats something else youll have to look into because the driveshaft and trans more than likely arent built to handle that kind of torque as the rx7 made alot less torque than the 300sx by like double. that being said youll more than likely need to get your driveshaft shortened or use an aftermarket one and if you plan on bolting the trans from the rx7 up to the motor from the 300sx you will also need a bellhousing adapter
another problem which may not seem apparent is that your shift knob might not line up with the factory shift knob hole so you may need to handle that i know some companies make adapters or what ever you would want to call them im not sure if there is something of the sorts for your specific setup
lyric marsh
i was going to put the 86 rx7 motor and the 88 drive shaft in it if it doesnt work or doesnt seem fixable. id imagine the lining up wouldnt be too crazy considering theyre both super close in length. inches even. but i do see where youre coming from but if that was the case. this is my first project and i intend to put alot of effort into it. so i dont even mind making custom fiberglass pieces for the interior. now im just a little on the fence on what to get. this seems like something that is a really good what if though. idk i just dont like how people write off cars as a lost cause like that when you can do anything with these mfs if you have the right knowledge. although i cant get ahead of myself. i have to learn first