im ordering new richmond gears for my 85 trans am... and the only thing i am not sure of is the description of the gears says "GM 10 bolt 7.5/7.625" , and my diff. cover has 9 bolts... its a posi unit to the best of my knowledge...(inside has no spider gears or nething visible..) it also has disc brakes if it matters..

the gears im ordering are 4.10's
i had a f-body rear end before with 4.10's but i didnt install them and it was a ten bolt diff, ( not nine)

if anyone knows if i can use these richmond gears that say theyre for a ten bolt in my nine bolt rear end it would be really helpful
thanks, keith

 

No, those gears will not work in a 9-bolt. They are completely different rear ends inside. You have to have 9-bolt gears.