Im thinking of getting some gears and a posi trac for my truck. Need to know what size posi to get for my truck cuz im tired of relying on my g80 to give out. Also gonna start a build on a 408 stroker motor and a full build on my truck. Will be asking some questions in the future.

 

Is the rear ends 8.5 or 8.625?

 

8.6 is what you need

 

OP, if you have the 10 bolt, it's the 8.6" like Keniff stated. The 6.2 trucks did get the 14B rear.

Look up Ron's Machining Services for your differential parts. You won't find better help, or better prices than him. He can also sell you an install kit, and all of the bearings & seals that you may want or need for the job.

 

mine is a 10 bolt but its not a 6.2L it a 5.3L motor and your saying its still a 8.625 then

 

Yep, 8.6 10 bolt.