stipped threads on chain sprocket

[antonino]

Well all was going well on my job to replace a chipped chain guide rail on my 91 300CE / M104 engine...while I was there I decided to replace them all. I removed the tensioner since I was going to replace it to get the slack I needed but it was not enough to install the right hand side rail in place, rather than undo the chain, I opted to remove the 3inch diameter chain sprocket/idler that is attached to the front of the head on the right below the intake cam. I tried to loosen it but realized too late that this bolt is a lefthand thread and stripped the hole. As such, I cannot torque it to the 35NMs (27 ft pounds) it calls for. The sprocket rides over a sleve that is held in place by the bolt. I tried red thread locker but after letting it cure was able to break it free with a socket and little force. As such, is there any high strength metal to metal adhesive that would hold this in place. The hole is not entirely stripped since I am able to unscrew and srew the bolt into the front of the head...problem is once it mates with the sleve I cannot torque it down. I put a set of vice grips on it to see if I could pull the bolt straght out and could not. Since the chain rides on this, I want to make certain it does not come loose and really mess things up in there. PLease advise as the last thing I want to do is pull the head.

Antonino