ConcoursMustang Forums

1st Generation 1964 1/2 - 1973 - Questions & general discussions that apply to a specific year => 1970 Mustang => Topic started by: 1970 Snake on December 02, 2019, 01:32:43 AM

Title: Painted Numbers Inside Block
Post by: 1970 Snake on December 02, 2019, 01:32:43 AM

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

Title: Re: Painted Numbers Inside Block
Post by: RoyceP on December 02, 2019, 09:40:32 AM

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.

Title: Re: Painted Numbers Inside Block
Post by: J_Speegle on December 02, 2019, 06:58:40 PM

Quote from: RoyceP on December 02, 2019, 09:40:32 AM

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

(http://www.concoursmustang.com/forum/gallery/13/6-021219175804.jpeg)