[71swb4x4]

Any vendor should have a chrome fuel cap.
Do you still have your stock vent tube? It's inside the Blazer tub right next to the fuel filler tube. If it's still there you will want to hook your vent hose up to it. If it's not there, I am sure you can find one here on the board from someone that is parting out a Blazer.

Edit: After posting I thought that I may just have one of these in the garage. Sure enough, I did find one hiding out. Here is a picture. It has three lines going off it. I am sure one is from the fuel tank, one probably goes to the charcoal canister, not sure about the third. Maybe the third is a return from the charcoal canister????