More Buick 455 AC Bracket Information
by George Nenadovich
Photos by Dennis Wheeler
Here is a 71-up Buick 455 AC bracket set-up. This has the
welded steel lower bracket. Notice the notch for the alternator rear case
to clear the bracket.
Notice the notch to clear the valve cover with the welded
steel lower bracket.
Here is the upper AC bracket with the cast aluminum lower
bracket. Notice this one
does not have the clearance not to clear the back of the
alternator since the bracket sits above
the alternator case.
Here is a shot of the lower cast aluminum bracket.
Notice the upper AC bracket that goes with the lower cast
aluminum bracket has no notch to clear the valve cover since it sits much
Notice location of alternator adjustment arm bolt hole...one
sits next to the AC compressor slot and the other one sits above it(71-up)
Side by side comparison of the two upper AC brackets.....notch
the later version and also notice the position of the stamped
groove.......the end of the "V" sits
in the middle of the adjustment slot for the compressor while
the 67-70 version has it closest to
the outside edge.
Here is the end of the 67-70 bracket AC compressor slot....notice
how much further the adjustment slot extends beyond the bracket edge.
Here is the part number, 1235835, stamped on the bottom of
the 71-up AC bracket...the 70 bracket did not have this number.....not all
brackets will have numbers so reference the notches and stamped groove as
a guide to application.
Here is the complete 71-later welded lower steel AC bracket
and upper brackets.
Here is a side-by-side comparison of the two different alternator
adjustment arm brackets.....they almost look identical.
Upon closer inspection...often missed and causes frustration.....the
longer arm has the hole for the bolt that goes into the upper AC bracket
about 1/2-9/16" further away than the shorter version. The distance
between holes, center-to-center, for the longer bracket is 12"
Here is the complete set-up with the cast aluminum bracket
and long alternator adjustment arm.