Thanks to BlueOvalRage for all the research leg work on the 9" F-100 rear solution. I have found a 1971 Ford F-100 pickup that I can purchase the complete 9" rear for $50 (for my 56 Ford panel). I plan to have the axles redrilled for a 4 1/2 bolt pattern to match my Volare front clip. My question is, will brake drums from a 79 T-bird fit on the larger truck axle flange to provide a drill pattern for my local machine shop, or will I have to have the truck drums drilled? Also with the panel being a little heavier than the pickups, what do you recommend for the rear springs (would like about a 4 inch lowering)? Is there any way I can identify a "posi" without removing the carrier?
Thanks for the assist.

 

It's marked on the metal tag that's held by one of the carrier mounting bolts. bottom line - example 3 L 50 9 shows a 3.50 ratio limited slip (locker) 9"

 

MT
Thanks for the information. Maxx