Searching here:
http://cincinnati.upullandpay.com/search.aspx
Comes up with a 98 & 99 explorer. These should have the 8.8 you need.
Bring someone with you to the yard to help you check the gear ratio.
Out the door with brakes & all will run you around $250 unless you have a coupon from a previous visit there. Call them & they'll tel ya the exact price.
Pull the correct one, bring it & your old axle to my garage along with a pack of 4.5" cut-off wheels & I'll get the perches on the 8.8 for ya for cheap.