What's That Sound?

OK, I got some time and replaced the rocker arm, re-lashed all the valves again and took off the dust cover for the trans and looked for any issues with the torque converter...nothing changed. However, when I start the car the tap/knock isn't there. It comes in after about 30 seconds of running. Oil pressure is 65 psi almost immediately. It does seem to be more prevalent on right/passenger side now. I guess it could be an exhaust leak too so that's what I'll try next I guess.