# Production numbers

**URL:** <https://community.cartalk.com/t/production-numbers/27710>\
**Category:** Maintenance/Repairs\
**Created:** [March 13, 2009, 5:24pm UTC](https://community.cartalk.com/t/production-numbers/27710 "2009-03-13T17:24:52Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![chevyguy69](https://avatars.discourse-cdn.com/v4/letter/c/a88e4f/32.png) [@chevyguy69](https://community.cartalk.com/u/chevyguy69)\
**Post date:** [March 13, 2009, 5:24pm UTC](https://community.cartalk.com/t/production-numbers/27710/1 "2009-03-13T17:24:52Z")

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can any body tell me how to tell the year of an engine by the number on the block?the number is3970020.thanks

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**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\
**Post date:** [March 13, 2009, 5:38pm UTC](https://community.cartalk.com/t/production-numbers/27710/2 "2009-03-13T17:38:30Z")

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Any idea on brand, type, size, year, displacement, etc?

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**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\
**Post date:** [March 13, 2009, 6:04pm UTC](https://community.cartalk.com/t/production-numbers/27710/3 "2009-03-13T18:04:35Z")

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That would make it too easy.

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**Author:** ![chevyguy69](https://avatars.discourse-cdn.com/v4/letter/c/a88e4f/32.png) [@chevyguy69](https://community.cartalk.com/u/chevyguy69)\
**Post date:** [March 13, 2009, 6:33pm UTC](https://community.cartalk.com/t/production-numbers/27710/4 "2009-03-13T18:33:54Z")

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the eng is a chevy 350

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**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\
**Post date:** [March 13, 2009, 6:50pm UTC](https://community.cartalk.com/t/production-numbers/27710/5 "2009-03-13T18:50:41Z")

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That sounds like a ‘casting number’ and not an ‘engine number’. This site says it’s a 307 cid block, made from '69 to '73. [http://www.mortec.com/castnum.htm](http://www.mortec.com/castnum.htm)

You’ll need the engine number to know more. See [http://www.aacncclub.com/CHEVY\_CASTING\_NUMBER\_LOCATIONS.html](http://www.aacncclub.com/CHEVY_CASTING_NUMBER_LOCATIONS.html)  
for where to find it, and what it means.