CA-mazing

crazy idea right? buddy of mine wants to start a new project car and that is his grand idea. he's built two decent 240's with a highly modded KA and basically stock SR. but he said he wants to swap an RB into a 300zx. i told him that some serious work would have to been done in order for that to happen. he said it wouldnt be too bad once he got the motor in cuz everything about the car is setup pretty well. he's looking at an '85 300zx w/turbo. makes sense cuz he would already have a boost guage and just install or swap a few other. and it comes stock with 5 bolt pattern, i dunno about an LSD, have to look into that.....but i still dont know about fitting that engine in there. what do you guys think? personally, i've never seen an RB of any sort in a 300zx