Original GM lower and  12 1/2" upper alternator mount used on Small Block Chevy V8  and GMC trucks from 1969 to 1972. The lower cast alternator bracket has GM part number 3951337 as seen in the 6th photo and was also used in 1972-78 Corvette's with LT 1 engines. Great problem solver for hot rod/street rod small block Chevy engines using 1969+ heads with accessory bolt holes to mount alternator when using headers and short water pump pulleys. The last photo depicts mounting for reference in my 1972 GMC K5 Jimmy with small block 350 V8.

These are getting harder to find and the "aftermarket" attempt to copy are in my opinion...JUNK!!

Check my Other Items for more original parts and brackets.