[Jthompson]

That tapping is likely your mufflers hitting the frame. Be sure that they aren't hitting the driveshaft, and producing the smoke you see.

I believe, though not 100% that that tube comes from the smog pump and injectes fresh air into the pipes to finish burning the fuel, etc. Reconnect that. You can used rubber hose if need to connect it to the hipe if you used a hacksaw like I did to cut it off.

Did you scribe a mark on the driveshaft to line it back up properly when you put it back on??? The driveshaft could be out of balance now.

Also, be sure that your u joints are ok. Make sure that all of the bolts connecting the bell to engine and bell to tranny are tight.

Lastly, did you resurfact the flywheel? Did you put it in back right and torque down properly??