How much do I torque down headder bolts and intake manifold bolts?!?!?!?! Sorry I want to get this done tonight!!!!

you might think of going to studs insted of bolts. any way the smaller bolts tighten to 10 to 13 lbs and the larger ones 25 to 36 lbs. remember the 10mm bolts are two lengths the shorter ones go into the center holes and the longer ones in the outer holes.

The top header stud coming out of the engine closest to the radiator is broken off. I installed header and every thing seems to work well. Could this come back to haunt me?

You most likely will have a leak eventually and need to remove the broken stud. In removing rusted bolts and nuts , I have found Kroil to be the vary best to penetrate the rust and allow removal. The secound best is PB Blaster, only it smells vary strong . I work in my attached garage and it stinks up the house . Kroil works better and doesn't smell. I dont know if it would have made any difference in your case but I just wanted to pass on the info.

if you have a leak in the exhost port up front , it can influnce the thermastat and temp reading.

I would also think leaving a bolt out could lead to a crack in a cast exhaust manifold or warp in a header.

Just a thought.