lightweight alternator

[Steve AKA vitessesteve]

I bought a lightweight Nippon Denso alternator some time ago and have only now got around to fitting it.  

Question where does this bit fit in?

A photo showing a fitted alternator would be great.

[JohnD]

That's a spacer/bolt, to align the alternator pulley with crank' and water pump pulleys.
It's instead of a single bolt through the pivot hole on the alt. and the bracket on the block.
Without being there, can't tell if it's suitable, but washers as shims can pad it out if the central spacer isn't thick enough.

Looks from the photo as if one end is thicker than the other - should be obvious which way around it goes.

BUT, this may not be for a Triumph, unless you bought it as such.
If it doesn't suit, take it back!

JOhn