Getting a weird tick sound
I'm hearing a weird tick sound that seems like its coming from the center of the cab on the engine side of the firewall. It sounds like a little rock hitting the cab. Doesn't matter speed or RPM, and it seems to happen every 20 seconds or so, but sometimes skips a beat. I just bought the pickup which has been sitting for 3 years, so I have no basis to judge if I've lost power or not. I've change plugs and looked at the wires at night and see no sparking. I've tried regular and super unleaded gas and it hasn't changed. I had to put in a clutch and master cylinder when I got it. I tore the tranny back out to make sure I didn't do something wrong, and all looked well and put it back together.
Anyone have any ideas?