I have installed many a gas valve but I have never converted one. Is the location of the nozel in were the gas line meets the gas valve

Make, model and year of furnace? And are you asking about the orifices? I just have to ask, are you sure you should be changing out gas valves if you don't know where the orifices go or what they look like? Working with gas and gas controls can be very dangerous, not to mention a HUGE liability, and really should be left to the pros. Im not trying to be an *** or anything, just want you to be safe.