I broke a drill bit in the one broken rear stud trying to extract it. Anyway, I was still able to drill it and extract it but didn't trust the thread in the block any more. So I drilled it out and tapped it for a 1/4-20 helicoil. I wanted to raise the motor in the frame a little so bought the sickbikeparts front mount. For the rear mount, used 1/4-20X4 grade 8 fully threaded bolts. I'll be surprised if this new mount gives me any trouble, but you never know. Next time I'll use shorter rear bolts LOL. I took these pictures before putting the exhaust mount back on the bike: