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Author Topic: Painted Numbers Inside Block  (Read 1072 times)

Offline 1970 Snake

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Painted Numbers Inside Block
« 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.
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Dearborn Built Sept 4, 1969
1970 Mach1 428 CJ R-Code C6
Calypso Coral, White Deluxe Interior
dash tach, front bumperettes
Marti report one of one with delay wipers

Offline RoyceP

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Re: Painted Numbers Inside Block
« Reply #1 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.
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1968 W code 427 Cougar XR-7 GTE Feb 23 Dearborn C6 / 3.50 open
1968 R code 428CJ Cougar XR-7 May 13 Dearborn C6 / 3.91 T - Lock

Offline J_Speegle

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Re: Painted Numbers Inside Block
« Reply #2 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

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Jeff Speegle

Anything worth doing is worth doing concours ;)
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