I am trying to become more knowledgeable about this car and am slowly learning all the new information about different parts of the car. Well this brings me to which transmission is in the car and what bolt the rear is. It is a 91 RS with the auto 305. Also, is there a place or thread that explains the difference between 9 & 10 bolt rears and what the advantages are to either of them along with the gearing. Excuse my being a complete newb but I couldn't find a database/sticky of any sorts like there is in the TBI section or exhaust sections. Thanks for all the help

 

you can tell what rear you have by counting the bolts. 9 would be a 9 bolt and 10 would be a 10 bolt, pretty simple to figure out. 9 bolts wouldn't be fctory installed. a 9 bolt has a larger ring gear and is stronger than a 10 bolt. the trans would be a th700r4, if it's original.