I'd keep the hand valve. My truck('84 K10) switches with an electric valve. The switch on the dash does both the tank and the sending unit. Problem is that if you don't use it often, the valve can get sticky and not switch. The sending unit switches leaving you thinking that everything is fine until you run out of gas on the empty tank that you thought you had switched away from. One of these days I'm going to put a manual valve in. Then I will know for sure which tank I'm drawing from.
