[MrPbody]

Yes, Cleveland and Windsor share the bellhousing bolt pattern, along with 289 (late) and 302 (and 240/300-6 of all things...).

Look at the case. If it's iron , with aluminum bell and tail, FMX, no doubt. If it's all aluminum, and has an integral bellhousing (not detatchable), C-6. All aluminum, and bellhousing can be removed, if the bolts holding it on go through the pump housing, C-4. If the bolts do NOT go through the pump housing, C-5.

FWIW, EVERY 351C 2-bbl. I've ever seen with an automatic, was FMX. Every 351C 4-bbl. was C-6. Those are cars I HAVE SEEN. I won't dispute oddballs. I've seen some pretty strange stuff over the years, so very little surprises me anymore...

Jim