I inquired about a 12 bolt rear end to buy today and the seller mentioned series 2, 3 and 4 carriers. I didn't realize there were different ones. What is the difference and is one better than others?

Each size carrier is for differenr size gears, such as 2 series will hold all the sizes in the 2s such as 273 and maybe a 308 max/ 3 series will hold up to a 373 and maybe a 410 with an adapter, 4 series will hold from a 373 up to 488s and so on and so forth, I have a 4 series 12 bolt posi and 410 richmond gears for sale if u are interested, Good Luck L89SEDAN

Thanks L89 but I'm up in BC Canada and found one locally for $500.00 which is about $25.00U.S.(A Canadian $$ joke)I appreciate the info.