Hi everybody, new here on the forums. I'm gonna cut to the chase with my little problem that I'd love to solve. In my currently daily driver 1965 Mustang coupe, my 200 seems to have a knock. The thing is, at first it was a tap, and has escalated. I have all original parts. I recently dropped this engine in after buying used for $150. Old engine decided it was gonna be a 200 five cylinder. I have already replaced the fuel pump with one I know makes no noise, hoping it'd be a simple fix like that. Nope. now the noise itself is hard for me to get a location, but the sound is a tapping that does not increase or decrease in pitch with change in rpm. But the noise does get faster or slower with the rpm, respectively. I've read about dents in the oil pan, and climbed underneath. I saw no visible dents, and decided not to pull the pan. Anyways, any experts willing to lend a hand and help me get this solved? (Don't want to just drive until it dies.)