I have a 1989 chevy blazer. We put new cylinder heads, adjusted valve lash according to book.Now it wont start?what did i do wrong? it has new battery. Engine turnsover like it wants to turn on but doesnt

So I have an 1989 Chevy Blazer 5.7L I have replaced the heads in the blazer and did the valve lash adjustment. According to the book. But It was running rough. So again I adjusted the lash accordingly starting with the TDC#1 then tightening until the rod didnt move, then turning 1/2 a turn, then rotating to TDC#6 and adjusting those intake and exhaust. However after I finished the adjustment of TDC#6 I checked the ones I did on TDC#1 and the some of the rods were loose.
Im not sure if it was a good idea but i rotated back to TDC#1 rechecked the intake and exhaust. Some rods i was able to turn with my fingers so I tightened enough till rod didnt move and did a half a turn. and then the same for those on TDC#6. But each time I rotate to check some rods are loose. WHAT AM I DOING WRONG? (before i start it up tommorow I dont want to mess anything up)