I have a 88 transam 305 tpi auto i know i have 2:73 gear ratio with posi but do i have a 10 bolt or a 9 bolt and what series carrier 2 or 3 i want to order 3:73's for it and dont know what i need thanks for the help.

 

Well its difficult to say. All of the TPI TA's Ive seen have 9 bolt posi rear ends. Your going to have to crawl under there and count the bolts on the differential cover. If It is a 10 bolt and 2:73 gears its a 2 series carrier. #1 is the order no. you will use for ordering gears.
SSC

 

What is exactly a 9 bolt rear-end? I know what a 7.5 , 10 bolt rear end is. What is the difference between a 10 bolt and a 9 bolt?

 

The number of bolts. The rear end is completely different, and as the name implies, the cover is held on with 9 bolts instead of 10 like on the 10 bolt. The 9 bolt is a lot stronger than the 10 bolt, and has the advantage of being able to shim the cones when the posi starts to slip, but parts are hard to find and expensive.

 

Hard to find. NO - I have gear ratios up to 4.10 available. Also new series 3 posi carriers and other stuff. All the info is on my page at www.koolmeister.com

Expensive. That's relative. To a weak 10 bolt, yes. To a complete 9 inch or 12 bolt, no.

Miles

 

THE 88 AND 89 B/WS ONLY HAD 2.77,3.27,AND A 3.45 GEARS.IF YOU FIND THE AXL CODE SEE IF THE FIRST THREE CARICTORS ARE, GH3 "2.77 B/W 9 BOLT POSI", 6HT "2.73 10 BOLT POSI",OR 6HP "2.73 10 BOLT STD".IF ITS SOMETHING DIFFERENT POST IT AND I CAN TELL YOU WHAT IT IS.HOPE I COULD HELP,LATER