Went to help install a engine/trans at a friend's yesterday, had to install the sump first. Realized that the aluminum-case threads were badly stripped. Went to Ace hardware and got three 7mm x15mm long hex screws, and one 7mm x 25mm. Cut grooves in the long bolt with a file to tap the threads, ran it in once each hole. Then the new 7mm bolts went in snugly. Saved our bacon.