Its prolly hard to say since 302`s were built since 68 till maybe late 90`s or later. I forget when the last mustang had one. Yours could be any combination of block,heads and intake. I believe one way to identify the pre 70 engines was the number of bolts used to hold the pulley to the balancer. I think pre 70 had 3 and later was 4.
The number you refer to above the starter is not stamped but cast into the block. All ford part numbers use the same system , a prefix, a basic number and a suffix. Example D5tz-6500-A The D is the decade the part was first introduced B=50, C==60`s D= 70`s and so on. the second digit is the year, The third is the model of vehicle ie: Z= mustang,T=truck I forget the others I`m not sure about the 4th, The basic number identify`s the part I believe 6500 is cylinder block, 9510 is carb thereis thousands. the suffix may be revisions to the part. Idont speak real fluent ford part numbers but this will give you a ruff idea.