Engine Removal, Rebuild, and Re-installaion

[Jamesp]

It's alive!!!! bu wa! ha! ha! ha! ha!!!!, Got the engine re-installed and cranked it up. Cranked and idled smoothly at first, then the idle fell off and got thready, a little gas to keep it going and then 3 bangs and I shut it down quick. I was sure that was curtains and the CEL came on. It threw an O2 sensor low voltage, a "random misfire" and misfires from both sides of the engine. Nothing ventured, nothing gained, I fired it back up. Much less drama this time. It was still searching for idle, and all the oily hand prints were buring off the engine. So I shut it down and cleared the codes. It fired right back up again and I let it get warm at idle, took it to 2000 rpm (very smooth) then back to idle for a bit, 2500 rpm then idle for a bit, 3000 rpm, then idle all smooth. Idle was much improved but not perfect. Gauges seemed proper, no warning lights and no more CEL. BUT, when I put it in gear, and let the clutch out, it made a noise like clashing gear teeth. My thought was it sounded like the flywheel just touching the starter gear. It did that twice and then quit. Ideas?