do i have a 427 bbc

[mikedillon]

Okay i came across this forum while searching out bbc casting numbers,so if some one would please help me verify what i have.I bought a 86 chevy dually running driving for 1000 because i wanted the 454 an th400 for my 57 chevy bel air,only its not a 454 i think its a 427.Casting on back reads 3916321,on front pad its T0206I0 with next to it vin 18s411897......could i have actually hit the jackpot so to speak.Thanks in advance for verifying this.