Originally Posted by NorCal DC4
The B18A made less power, and had a marginally lower redline.
The B18A had less static compression compared to the B18B, and the stock cams were more conservative.
As far as I can tell, all 90-01 B18A/B engines had a 9.2:1 static compression.
Anyway, the main difference is in the 90-91 B18A, it's was a little lacking at 130hp, 121lb-ft. The 92-93 B18A was rated at 140/126, and if memory serves, the B18B varied from 142/126, to 140/126, then I could have sworn I saw a sticker on '00 and '01 models dropping it down to 138/126 thanks to emissions laws.
Anyway, stick with a 92-up engine unless you want to swap a pair of newer cams into a 90-91.
After modification, they're all the same.