Diesel Bombers - New guy from Houston

Hey guys, new member and first time diesel owner from Houston. Just picked up a project from my fiances grandpa. 1980 C10 deluxe with the olds 350D motor. I'm debating between keeping the 350 and restoring it all back to original with a small 2-4 inch lift, or taking a 12v cummins from a 92-95 dodge and swapping it out with a 5speed and building it all up. I'd ad brackets to areas of the frame to strengthen it all but we'll see. Input will be appreciated.

My other vehicles are a 2008 Tundra 2wd 5.7, and a 2002 Jeep kj liberty(fiances).

Hoping to learn a lot here.