rear axle seal helpp!

ok, so i need the seal that goes into my rear differential. like where the driveshaft goes into it. i called summit and they said i have to call a parts shop so they call tell me what kind of rear axle i have. so i did. then they told me to call a mazda dealership. so i did and they said that since my truck is so old they cant do something iwth the computer? or sumthing?
can anyone help me with this! it would be greeeeeeeatly appreciated!!

bump it up for ya

haha thanks. cmon someone out there has gotta know this.