"ticking" noise

I have a 90 Camry (2VZFE 2.5L LE w/120,000 mi) and a get a ticking noise under load or while accelerating. I thought it was a bad Cam bearing, but it doesn't use bearings on the cam. I thought it might have been a bad valve, but I took the heads to a credible machine shop to have them cleaned, pressure tested, and valve seals changed. They said everything was good and changed the seals.
After replacing the Head gaskets (and every gasket above) and the MAF sensor, I still have the same ticking. I no longer have the antifreeze and unburned fuel smell coming out the exhaust.
Also. I'm not mistaking it for the somewhat noisey fuel infectors. This is louder than they are, and is in additon to that noise.
It sounds like the upper part of the engine, but I'm not ruling out a bad rod bearing or piston pin. Any suggestions?