340 Static Compression Numbers and Test Procedure

Theoretically it could be anywhere, but you will be most accurate a little before the crank reaches max throw and the vertical velocity of the piston is nearing zero. So you do it on the compression stroke, just before the piston reached the top, mark it, reverse, mark it, and then split the diff between the marks to get the real TDC. I guess you could mount a pointer and do it directly on the balancer but the degree wheel is easier IMO.