This is the first time I've installed the heads on my '73 Sport and I notice there are spaces between the head and the barrel on both vertical and horizontal cylinders with the nuts snugged down. Roughly 30 thou on the front cylinder and 20 thou on the vertical. Is this normal? Also, I can rotate the engine by hand, but it's fairly tight. (That said, there are new pistons, rings and barrels.) Any insights appreciated.