I personally hate seeing a decent truck body destroyed by chopping the top or modernizing the dash/interior, but a newer chassis and engine, basically non-visible upgrades, could be fun.

1957 Chevy 3200
Daily Driver
PS, A/C, Tilt column, Rebuilt 350, Rebuilt TH350, Reupholstered Bench Seat, sound proof/insulated, LED headlights/taillights/backup lights/interior courtesy lights.
Follow in the DITY