My engine has always run well, but I was curious about testing the compression on it as it is a 1986. To my astonishment, cynlinder 1 and 2 were at 115...and 3 at 80 and 4 at 75! I read in my Clymer that when two side by side cylinders have lower compression readings, that it may be the head gasket.<br /><br />I still need to do the wet test by putting oil in the cylinders...<br /><br />My question is, do I need to remachine the head flat before installing a new head gasket?