Something we learned on our last small-block Chevy supercharge escapade has to do with MLS head gaskets. The gasket we used was the older, tried-and-true Fel-Pro 1010 gasket that uses a preflattened copper wire. While this gasket works well for normally aspirated engines, it’s not the best choice for supercharged applications. According to the Fel-Pro engineers, a better choice would have been the 1003 gasket with a steel, preflattened wire, but the best overall gasket would be an MLS. This is the abbreviation for multilayer steel where the gasket is actually three or more layers that are riveted together. This multiple layer construction allows the gasket to better survive the severe cylinder pressures encountered with supercharged applications. For the Gen I small-block Chevy, they recommended the Fel-Pro 1142 gasket, which is for 4.100-inch-bore engines and despite the MLS design, is still only a 0.041-inch compressed-thickness gasket. There are also Fel-Pro MLS gaskets for bore sizes of 4.165 and 4.200. Now you know.