I have a 1987 260E showing 152000 miles, I discovered testerday that I have 4 stripped cap bolts. I understand it is possible to heli-coil the threads and replace bolts. Is it this easy? If I were to do this, what size drill bit, heli-coil, depth of bit, where to find new cap bolts??? Or anything else Ineed to know would be helpful... thanks kevin