I did use the shop air and rigged up a line with regulator and hooked up to the plug holes however it seemed the air was all going into the crankcase and it was hard to figure out if the air was going out the exhaust or elswhere. I did find what looks like bad rocker arm geometry as a couple of the adjusters were backed up into the rocker arms and the cup on the pushrod was close to or touching the rocker arm. I set the lash on all of the valves which all of them were out of adjustment and all were less than the .028 and .032.The inside of the valve covers and lifter gallery were all very clean so i think this engine was rebuilt not many miles ago. Also the cam does not have bad lobes and there are no bent push rods.