Kevin's info is spot on for the original part number on the solid lifter in question from the 1929-57 Parts Catalog.

The 1958 Chevy Master Parts Catalog provides the added info that GM# 5231445 was replaced by GM# 5231800 as of 3-1-58 (see links 1 & 2 below).

The later 1979 Chevy Master Parts Catalog indicates the correct GM# 5231880 (not 5231800) applies to your '57 engine (same for 235 or 261).


http://www.gmpartswiki.com/getpage?pageid=210786 (See note with 3rd link below for error info)

http://www.gmpartswiki.com/getpage?pageid=211286 (See note with 3rd link below for error info)

http://www.gmpartswiki.com/getpage?pageid=21163 - Apparently the 1958 Catalog had a typo as the later 1979 Catalog indicates GM# 5231880 is the correct one for ALL 235/261 6 Cyl '56-'62 + '63 w/4WD with the added detail "(2-3/16" long-two piece)".

Hope this is clearer than mud???

Dan

EDIT: The 2-3/16" length measurement specified in the '79 Catalog converts to 2.1875 (within 0.0005 of your original measurement of the "short" lifters).
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Last edited by Gdads51; 04/13/2023 2:01 PM.
~ Dan
1951 Chevy 3 window 3100
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