I have a 57’ truck with the stock GM 55T rear axle. I searched this forum for information about upgrading or converting but most are on the 55p rear axle which I found are not interchangeable with the 55T. Anyhow I just installed a performance built 6.0 LS 11:1 compression with the Holley sniper throttle body fuel injection and a MSD 6014 box and a built 700R4 transmission. Now I know it’s got a lot of power I’m guessing above 500 horsepower. This is a street truck but it’s got the power if I need it. With that being said I cannot hook up at any speed because of the peg leg driveline. I can’t seem to find a posi track for this GM55T unless someone on here knows where I can pick one up? So my only option is I have two GM 10 bolt rear axles both are 8.5 out of an early 70’s F body. Does anyone know what parts I need to convert to this 10 bolt? Also the 10 bolt will be upgraded to 30 spline Eaton true trac with the 6 bolt lug pattern and 4.10:1 gears. Thanks for the info