• As said by Baube, a 1973-80 model. More precisely, a 1973-74 one, due to style of the fender badge;
• If I'm not mistaken, this badge says that this pickup has the Cheyenne Super trim: it shows 2 words with each having a small vertical bar that projects downwards below the row. The only other trim levels available in 1973-74 were Cheyenne, Custom Deluxe and Custom..
• It's also a C-30 'Big Dooley' Bonus/Crew Cab. What's weird is that only the right side has DRW...