Large triangular passenger side bracket? I thought that was H body up until 00. You talking about the one that makes changing belts a PITA?
the large alum bracket is the low mount one 00/01+ where the earlier mount is the iron ball mount that makes changing the belts a PITA unless you do a couple little mods to the bracket
cut the lower hole into a slot and grind a 45* angle on one edge of each end of the spacer sleeve so it looks almost like a parallelogram e.g.
______________
/_____________ l
l_____________ l <center hole
l_____________/
to change the belts after this all you do is loosen the lower nut, unthread the stud from the block and drop it down and you can change both belts easy when you ensert it you just spin the sleeve so the flat untouched end sits against the unslotted portion of the lower bracket hole.
ive done it to countless G/B/H/C bodies whenever i have to change the water pump/etc and i have the bracket out.
did it with cody's (turtleman) riv and he loves how easy it is to change now