Alternator brackets 1st and 2nd Gen ? ?

[opelitis1]

Need help in figuring out what is original on the 1st Gennie brackets and on the 2nd Gen brackets I have from the left the mystery bracket then a 454 1977 bracket and on the right is a SBC bracket.
    The mystery brackety could possibly be a Firebird 1975 model. Look at the size of this one compared to the Chevy brackets. Actually the SBC is larger than the BBC bracket.
     On the First Gen. brackets, are these original GM units or aftermarket??  Figured I'd start over on this subject as my first posting is a bit lower on the page..
Ted

[x77-69z28]

the top alternator brkt with the is an orig small block brkt 69 vintage. should have a clip on top for neg batt cable and a hole for the clip on the alt. harness. the other tw look like later model big block brkts. in the upper pic, the upper left brkt looks like the lower alt brkt on my 67 rs/ss 350. it bolts to the top of the exhaust manifold.

[flyingskibiker]

You know what I did to figure out what extra bracket came w/ a purchase I made?  I went online to the vendors w/ good pictures and matched it up!  Turns out I have a '69 SBC power steering bracket.  Maybe you could try that, too?

[Marty]

The upper left bracket on the top photo is 6 cylinder lower alternator bracket. The upper right bracket on the top photo is short water pump small block V8 lower alternator bracket (i.e 67-68).

The lower steel brackets in the top photo look like brackets used when you install headers.

Martin