+1 That's what I do. Worked for me on primary cover.

 

+2 same here, they are money well spent

 

theres a big difference on using a hand impact wrench on a 1/4" cover bolt and a 10 mm bolt torqued to 20+ lbs.

 

Finaly got em off tonight! Found the primary problem was a socket that didn't allow full engagemant ofer the bolt head as the socket wasn't deep enough. Saw the problem after it was too late on the right side. I had another socket set that had was deeper ( but not a deep well as all mine DWs were 6 pt) and the left side came off like all of you said, with a little tap on the drive. So even as the left came off ok the right was still a problem. Got the fender off and pulled the right side pads out of the caliper to free things up a bit. Next it was torch heat and vice grips.....no turning back now. They would not budge but it was impossible to generate any torque with V grips as the spun, grinding the bolt head into mush. Someone recommended a Sears bolt removal set. Figured I had nothing to loose so invested another $30 into the cause and they worked great. Had to hammer the right size on the bolt but as soon as it was installed I could tell it was snugged up tight and holding torque. Could use a 1/2 drive and a hammer strike and thank you sweet Jesus they broke loose. Goobered up the bolts but new bolts are a small price to pay after investing $50 in the process. Sucessfully getting 'em off ....priceless. Time for a celebration beer ....or 6. Thanks for all the great advise ....thought I'd pass along my learnings.