Pulley Question

Check this post of today:
"Small block manual steering no a/c pulleys and alt bracket"
Answers your question, but is it worth $100 to you? I could live fine with the original 3-pulley, but I am cheap.

Another kink is that some SB crank pulleys had equally-spaced bolts and some had an offset bolt. I think they changed to the later ~1966.
A final kink is that if you later install an after-market crank damper, some are thicker (thus moving the pulley groove).
So, KrazyKuda isn't crazy to keep boxes of pulleys around.