Here is my update on the current status. I decided to use Permatex Ultra temp gasket maker (copper color) after contacting their support. The broken bolt is untouched - after a lot deliberation I decided against trying to remove it. Firstly, it is the bolt never used by the factory. In another thread somebody referred to an expert telling that Pontiac didn’t use the outer holes (at least for a couple of years) to enhance the longevity of the exhaust manifolds. Secondly, I wanted to come to an end :-) .... The only issue with silicon and working alone is to get the manifold in position so to insert the bolts without smearing the RTV all around and away from the area to be sealed. I intended to use the studs from the manifold to the down pipe as guidance in 2 threads of the head since they have the same thread size and are long enough to be safely removed and to use the bolts. But I forgot it. So I went along and mounted the exhaust manifold smearing the RTV only a bit (and fearing to have to do it again). While checking the driver side exhaust manifold to see the tabs on the outer bolts I discovered a leak between exhaust manifold and head. I decided to give the RTV a try and prepared a syringe with a hollow needle to insert the silicon into the gap, which worked as expected. Furthermore, I checked the scews of the atm oil pan and discovered that they hadn’t been nearly fastened with 12 lbs ft. So I tightened them according to spec. BTW: drops of ATM oil were hanging on many of these screws. Today I have test driven my Firebird. First only a few miles than increasing the circles around where I live. The splashing sound during acceleration is gone. If the engine fumes - noticeable inside - are completly gone remains to be seen ... I had the windows down because we have a nice day today. More driving will show if the RTV does its job. If the driver side spot keeps being seald, remains to be seen.
