Hmmm. Well Ive never attempted to use 99-00 si axles with a 88-91 B series swap. I was always afraid theyd be too long. Ive always used 90-93 integrea non-abs axles with the Half shaft. Remember the axels you get, make sure you have the matching half shaft. For example- 88-92 Civic/CRX SiR axles will not work with a 90-93 integra half shaft properly, my own experience on this one. DOH!!! I say, find someone who will trade the 99-00 si axles and half shaft for 90-93 integ, or 88-92 SiR CRX/Civc axles and half shaft. Make sure you don't get ripped off like getting a half shaft that has bad bearings n shiz. Any other questions with your USDM 88-91 B-series swap, just post em up man. Have fun with VTEC! better than secondarys on a carb'ed 350!