Problem solved on the engine mount itself. The M8x1.25 bolt stripped out way prior to the specified torque. I had a machine shop quote me $150 to machine some custom steel sleeves for the M8 and two M12 bolts that goto the engine bracket. The engine bracket is cheaper than that new so I didn't go that route, though they would never strip or pull the threads again.
I loosely installed the mount and engine bracket so I could torque the two M12 with the 18mm head to the 74 ft/lb spec to see if they would take the torque. Although the threads look pretty buggered the first half inch or so they seemed to grab plenty well and took the torque no problem.
The only issue then was the M8x1.25 that was totally stripped out. I've been using these keyed locking thread inserts lately on other holes that had stripped or damaged threads. They really really work awesome. I get them from McMaster-Carr. You have to drill the hole to the specified size for the outside thread diameter, which in this case was with a 10.8mm bit. Then you tap the hole to M12x1.25 which is the outside thread of the inset. Screw the insert in until it bottoms out on the keys then use the special tool to drive the stakes perfectly and evenly down into the aluminum. This prevents the insert from backing out with the fastener like helicons and others can do.
For many projects I've become fond of these inserts. I don't think they would work for spark plug holes or anything like that. I would go for the timeserts for that I think, they also are designed to be staked using another method and will not back out. These keyed locking inserts would be way too thick for a spark plug or something like that. I used these style inserts on some M6 transmission pan bolts that went into the aluminum Toyota transmission case they got cross threaded and stripped by someone in prior years. They work like a charm and aren't going anywhere. They also make them in stainless steel but I'm been using the black steel variety for my uses up to this point.
