When I blew my H23A1, I replaced with an H22A4 in my 1992 Honda 4WS. I got it at the site below. I am sure they have H23s but I would go for the more HP.
http://www.importautosalvage.com/:smoka:
Check out the H22A w/LSD for $3300
http://www.importautosalvage.com/database.htm
(View entire database)