Blast or not to blast

[sunbeam39]

I've got iron heads from a 3.4 SFI that had 95,000. I want to clean them up and thought I could use the #6 glass bead in the blaster?!?!?

[Superdave]

iirc, glass works better on aluminium but i'm sure anything fired that fast at cast iron will clean it up pretty good.