I left my EFI tank, ran new diesel rated rubber lines to and from motor, 18' per side. the Cent is essent an ex cab shrt box as far as wheelbase goes. Stripped the high psi pump off the gas sending unit, left the gasser sending unit, and then reassembled.
I can get you a 7.3 E40D truck here 4x4 1992, NA, needs rebuilt, runs beautiful, just likes the oil.. for $2k, maybe less... ex cab. Betcha if ya offered $1500 + fees ($300 = 6% and $13 title fee) yer an owner. swap out its needy 7.3 for your 6.9.. save the manual trans stuff for later down the road.