Things Change.. Butters is now getting a 392

I've been wanting to switch to a 3.55 and get rid of the slipping cone type sure grip. Based on cost alone, this is sure looking like an attractive option. Did you grab the u-joint flange off the driveshaft while you were at the junkyard?
Nice thing about Ford 8.8 is you can change the Traction Lok clutches with the differential kept in place in the housing. No need to disturb the backlash gear mesh setup. And you can shim the Traction Lok clutch packs tight to get more grip. I added an extra clutch on each side in the rear of my '88 fox body for extra lock up grip. And those rears are strong able to take a lot of abuse.