86 22re engine misfiring

[fire5]

hello toyota nation. this is my first post so here it goes. 86 4x4 pickup, 22re engine, 187500 miles. here's the problem maybe long winded.
truck was running fine and began a long haul of approx. 3000 miles. began to suspect timing chain wear a little better than halfway. had previoulsy tweaked the timing on a couple of occasions. got home and decided to go ahead and replace the chain. tried one last trip to a buddies cottage, stopped for gas, started out to the highway and got 100 yards and my baby died. towed home got my parts and started a tear down. yes the chain had broke along with the crank sprocket.
o.k. rebuit everything and after starting got it going again but with a really noticeable engine missfire. the engine shaked around badly with a more noticable tapping then ever before at the valve cover. also clicking sound from the distributor which was there a little bit before the long trip. one more symptom - hissing that honestly seems to be coming from the large air duct at front of engine between air filter and intake, loudest pretty much right in the middle - beats me.
tore the engine down checked and adjusted valves, no obvious deficient vacuum hose damage or connections. there was corrosion in the distrib. cap on the four metal nubs. also made doubly sure all timing marks lined up and that engine is at tdc.
with engine running in garage before second tear down i was suspecting the timing chain might have come askew.

so, thats where i sit right now, about to put the valve cover and distrib. back on and see what happens, and wondering considering whats been done what other things i should look at to hopefully fix this.
a vacuum leak wouldn't cause that much engine misfiring would it?
One more thing, i didn't change the tensioner the first time, (don't know why) and when I had the timing cover off the second time it didn't seem to be tensioning properly, so maybe the chain jumped a tooth when I was installing the distrib. and tightening the crank pully bolt. Is this possible? I'm hoping this is just a timing error from the first install. Before I button everything up I want to exhaust all options.
Any help would be hugely appreciated (hope all this makes sense)