69 Dodge Dart Cummins Build

I'd say you're looking at a full tube chassis if it's been sitting on the ground like that for 10 years.

I wouldn't trust the Conquest rear behind a 4BT or 6BT, The Starion/Conquest rear does fine behind a mild V8, but it's not going to survive long behind a Diesel. I wouldn't trust the Corvette rear behind a Cummins either, it's nothing more than an Independent Dana 44. You'd be better off building a custom Dana 60 Based Independent Rear, have Strange or Moser cut custom axleshafts to the length you need and have the WMS drilled to use Viper CV Axles (the Viper rear is also a Dana 44, like the Corvette), or step straight up to CV Axles for the front of a Diesel 4x4 pickup.

The 6BT will fit a Diesel 727 from an 89-91 Dodge Truck, a 4BT will too, if you use a 6BT Adapter on the 4BT