I can see the reason people drop an RB into an s13 (buy an old auto Q for next to nothing). But i still think its pointless if it had an sr20det to begin with, the performance differances are not that great, its not even a rare conversion anymore. I'd rather spend the cash differance on mods for the sr20. And some would argue (maybe even harder) that the differance again in price would be better spend on a ca18...
I know this is a pointless statment on a skyline forum but anyway...