both methods are good alternatives...I'm a fan of clay and checking springs...the math is a PITA that I recommend to none as many people aren't that good at it...you will also need lots of precision equipement to have exact heights of everything, including the block and HG thickness....aside from the previously listed.

For those donig clay and/or springs, be sure to account for piston wobble and 1/2 the main and rod bearings clearances.