I use a 1x2 piece of steel with some 80 grit sandpaper on it to do the final cleaning step. Thats after I use a scraper, wire wheel and a sharp blade on it. If it isn't flat and shiny then it isn't ready for a new gasket. I also torque everything down in stages - with heads it was torque it in sequence to 30 ft. lbs. three times to make sure all the bolts were at 30 and then I back them off completely in sequence. Then I torque the bolts in sequence again to 20 ft. lbs. and go over it a few times to make sure they are all at 20. Then I go up to 30 and go over them until I am sure they are all at 30 - repeat the process at 40, 50, 60 and 70. When they are all torqued to the final step and it is check then I move on. Since I started doing this I have never had any problems with blown gaskets or leaks from anything I torque down.
