Would you believe it???

[30psi]

Originally Posted by zxocmars

Why

It's simple

The first pulleys are wider and have some grooves across them
The second are V-shaped.

Will get pics on Friday

Part numbers for grooved pulley alternators are
23100-35f10
23100-D4410

The new one is Unipart GXE2403 - 258 769 (if it helps)

You said one was dual grooved Mk1 S12 is single vee, mk2 S12 is multi vee

23100-35f10 is S13
23100-D4410 is B12,N13,T12,T72