just got a 88 century, where to get info?

Hey all, I'm new to Buicks and GMs and I really have no experience except when they come in for oil changes in the shop that i work at. i have a 88 century 4door wagon with a 3.8 liter v6. how do i tell if it is a limited or custom wagon and what is the difference? what kind of transmission swaps could i do with shorter gearing? what are the hp/torque ratings? and what are some other good websites/forums with good buick info? thanks

oh and whats the towing capacity?