Hmmmmm. From 1969 through at least 1981, the 351W deck height was no less than 9.480", and no more than 9.503". Ford Motorsport offered SVO blocks with a deck height of 9.5" or 9.2", but I doubt either one of these blocks is an SVO. The 351C had a deck height of 9.2", and the 351M and 400C both were about an inch taller.
We need casting numbers.
Another easy way to tell a 351W from a 351C or 351M is by counting the valve cover bolts. The Windsor has 6, whereas the Cleveland and Modified both have 8.