need some serious help please

ok so i have been using the search for an hour now and cant find nething pertaining to a RB20DET swap in a 240sx with a j30 rear diff i dont know if a stock s13 or s14 drive shaft will work or not my old drive shaft is to short i used to have a ka24de tranny i finally found a rb20det tranny and now i needa know if my s13 driveshaft will work many people say a s14 drive shaft will but they all have a stock rear diff ........ any info on this problem will be greatly appreciated i am really lookin to avoid puncturing the rear seal to my transmission. that was one prob that arized while goin through all this in my head , and yes i did check the 240/180sx forums for the same questions ....once agian thanx for any help

If you have a 240, I'd just get the SR20DET if you have the cash to get an RB20. It's a much better engine. RB20's are a pain to find parts for. If you really want the RB though I'd go to some 240 forum or maybe even skylineownersusa.com. Those guys are pretty up to speed with things. They even have suppliers from Japan offer RB series engine parts for a lot cheaper than they are here.