I use rosin core SILVER solder. Suppose to be stronger than just rosin core. Available at Radio Shack (part # 64-013 E -- about $4.00). Remember to clean and roughen area to be soldered with sand paper and use tinning flux. Tinning flux helps the solder flow and also makes for a stronger bond. Been soldering clevises for years now and never had one fail.

I used the stock tank but replaced the stopper with one specifically for gas and have had no problems. Before installing gas tank with new stopper you may want to test it by filling tank with gasoline and checking in a few days -- just to be on the safe side.