Hi GLENN70
Found the source of the '69 coming with 351 Clevos. It's a piece written by KAR Auto Group in the US (supplied my repro door furniture). Here is the quote:
"virtually all 1969 351 V-8 engines were Windsors and virtually all 1970 351 V-8 engines were Clevelands. There are a few exceptions. Over the years we have seen a few 1969 Mustangs with factory installed Cleveland engines. By checking the build dates of these Cleveland 1969’s we found that in every case these Mustangs were produced in the last week or two of 1969 production when perhaps the factory ran out of Windsor engines. Conversely, we have also seen very early production 1970 Mustangs equipped with 351 V-8 Windsor engines. Again, perhaps the producing factory was using up their supply of Windsor engines before beginning Cleveland engine production. In either case we have found these to be very rare occurrences."
I took a look though my Mustang library too and found support for this opinion in Peter Henshaw's book, Mustang (Chartwell Books: NJ, 2005). In his chapter covering the '69, he states, "The mid-range cooking Mustangs used the 351-ci Windsor or Cleveland V8s".
While I always assumed that the '69 used Windsors only, I can see there may have been some crossovers in late69/early 70. My 351c is certainly after market as the Mach 1 was built in Mar '69. When I get her out of the shop, I will check the engine build date purely out of curiosity.
Anyway, just thought this was interesting.
