how to tell if my 68 is a stock bb

[schild09]

i had a posting similar to this but asking what the cst came with, now i am trying to find out how to tell if it is a stock bb or not, could be a stupid question but i am willing to hear that if i can learn something, this is my first classic truck so i am trying to get educated. i dont have the info on the backside of the glove box door, and if it was a bb it was swapped to a 454 and 700r4 (which is mean i might add). i tried vin but all i could seem to find is if it was a v6 or v8. thanks for any help.