Please post the pics you were sent, should make it fairly easy to discern between a small block and a slant 6.
Double check the number, it is stamped on a pad just above the driver's side pan rail- it should (but not always) start in "PK", then xxxxxxx. This will give us year and model info.
Thanks for the reply. I will look into posting those pics, but that requires a level of computer competence that I usually have to call my niece for advice on how to do that.