i am hooking up aftermarket water temp and oil pressure gauges.

water temp:
i got a 350 with the temp sending unit on the side of the block, so i would just connect new gauge wire to my present sending unit?

oil pressure:
there is a round plug thats pluged into the sending unit now, i dont use my stock gauges so can i just cut/split that wire and connect the wire from the new gauge to the round plug that goes into sending unit???

one more thing when reading instructions on doing this it says i need to run a wire from the gauge to the ignition switch. were is the egnition switch?

 

Usually aftermarket guages will come with thier own senders unless they specify you can use the stock senders. Remember the oil sender may have 3 wires if it has an electric fuel pump. 2 wires are to switch 12 volts for the pump after 4 psi is generated and 1 will be for the guage. DON'T cut the pump wires. By ign switch they mean any 12 volt source that goes on and off with the ign switch, you usually can find an open spot on the fuse panel to tap into that is key controlled.