my gauge came with a sender unit for the temp, but im not sure where I should put it. My question is can i just wire the gauge to the stock wires and use the stock sending unit? and if not where is the best place to place the sending unit that came with my gauge?

 

No you cant just use the stock wiring. Its unlikely that the calibration is the same. They sell in-line water hose adaptors with a threaded fitting for a sensor. If I remember right, the hoses are 30mm.
Im sure you can find a cheaper one, but this is the general idea...
http://www.jhpusa.com/store/pc/viewP...idproduct=2400

You'll want to put the sensor in the upper hose, so you measure the water temp coming out of the motor.