I'm pretty sure on my 79 Bronco 400 that it is dead center on the back of the motor, right on top. So, if you pull off your air cleaner and peer into the darkness back there, you should be able to see a round cannister a little over an inch tall and a little less than an inch in diameter with a wire connected to the top of it. It's just threaded into the top of the block, and mine was leaking like a sieve.