zeek

I have a 67 mustang with a 289 and I'm having some plug misfiring problems. When I got the car, it seems to have a rough idle but I didn't really hear any misfires. Yesterday I installed a new distributor, a new cap/rotor, and plug wires. I noticed a slight ticking sound coming from the passenger side of the engine. I also noticed a slight change in acceleration and a little rougher idle. I installed new plugs gapped to 0.035. This didn't seem solve the problem. The exhaust is now also popping under deceleration. I started the car in the dark and tried to see if there was any arcing by the plugs and i didn't notice anything. What's the correct way to diagnose this problem? Is there any way to diagnose each plug wire? Thanks.

89 fox

check your fuel pressure...sounds like it may be running lean..