so my rb20 is all but bolted in, but it seems that my driveshaft is about half an inch too long and i have no idea why. it is hitting the collar on the back of the trans. its the stock 5 speed driveshaft from an s13, but i do have a z32 diff which may be my issue, but it fit perfectly with the ka trans. i didnt put the diff in it so maybe theres some crazy voodoo going on back there, but is there something stupid and obvious that I'm missing? im using the mckinney mount kit too, if that helps.