I think only the top 3/4" of the 3" stud is threaded, but I suppose that might make it easier to thread the rest of the stud then cut it off like you suggested. I just want to be sure that a spacer is not necessary for proper operation. I have also seen an "insulator" advertised for the carb to manifold connection on 228 and 248 motors. Makes me wonder if there is a heat issue necessitating a spacer or insulator.

thanks for your suggestion