Topic: Painted Numbers Inside Block

[1970 Snake]

Can anyone advise why the painted numbers in the lifter valley and what they where needed for on my 1970 428 CJ motor.

[RoyceP]

Those numbers are for piston matching at the engine assembly level. The number represents the last digit of the bore size in thousandths of an inch.

[J_Speegle]

Those numbers are for piston matching at the engine assembly level. The number represents the last digit of the bore size in thousandths of an inch.

+1  And the workers assigned to that task (measuring and marking the bores) were quick!! Seen this demonstrated in a couple of movies made during the era. As expected. Do the same task over and over for days, months or years you get good and fast

Another example