I install the fuel lines on the tank first then feed them over the frame. The sending unit wire should be long enough to connect it as the tank is going up. Once you have the tank bolted to the frame connect the ground and hook up the fuel lines.
No it's not. The 203 shaft is longer. I just put a twin stick 205 behind a TH350 in my K10 and had to have the front shaft shortened and the rear lengthened.