Okay, next total guess, probably even less likely to work: low strength studs? Ones that stretch/ hold properly at half the foot-pounds? I'm not at all sure how you might achieve this, other than $$$$ or luck buying & testing cheap import "butter steel" studs in the right size. My dad was a mechanical engineer & I know that anything you spec can be made if you want to pay for it. If I had a spare junk block it would be fun to see if the insert idea might work. An aluminum one might be shop- made with a threading lathe, theaded outside & inside, with provision for a larger locating collar to locate the head on the block correctly. (Use a good aluminum alloy) The head would be fastened with a bolt from the top that goes through the head, the collar, and threads into the insert. I can picture this sort of in my mind's eye but I'm not confident it would work, too many things I don't know about motors, metals, etc.