it seems that headgaskets of different brands have varying thicknesses, do they compress down to the same thickness, or do they vary once torqued down?...I have a new Toyota gasket at .053 thickness, and an ITM at .075 (this part # is advertised as oem replacement, they also make an .020 over thickness) why would they make a stock replacement thicker? One would think this would have a dramatic affect on quench and compression (many of you have probably seen my thread concerning these issues) I have searched high and low to find a true piston to head clearance spec because no matter how far your piston sticks up out of the block or not, the headgasket's compressed thickness enters another huge variable that will affect this area. If we're picking over the details of a few thousanth's of an inch and striving for piston to deck height of 0 to +.006 or so and we suddenly have a headgasket that's .010 or .020 different than stock, during a rebuild all the details that went into getting that piston to deck height "perfect" for the sake of compression, detonation, collision clearance etc. have all just gone out the window unless we know the optimal distance the piston should be away from the head at tdc. a piece of clay on a tiny wire through the sparkplug hole would be the only way I can think of to measure that.