Over the years i have found that their is no correct way to build a car. Their is always going to be a way someone else would have done it. We use the aluminum mounts because they have an extremely low chance of failure. Those aluminum mounts are going to be a permanent fixture in that car.
As far as the L19's are concerned we are putting those in this car because the head gasket was already blown and their is just no sense in putting factory head bolts back in when we are already there. Yay for upgrades!!!