I am curious to what is the correct tightening torque for the engine covers using 6mm bolts (valve cover, alternator housing, drive sprocket cover, clutch cover, valve cover top cover). I am using gaskets w/0 sealant and socket head bolts with flat washers. I'm screwing into aluminum, of course. I was tightening to 8 ft-lbs torque until I had one strip out on me. Then I began torquing to 5 ft-lbs. Now I'm worried this may not be enough to prevent oil leakage. Anyone have good practical experience on the correct tightening for these bolts? Thanks.