Your VIN indicates 2bbl (8th digit, "T").

4bbl is listed in the break-down, but needs to be a "U" for 1983 to 1987.

Source: Haynes Publishing Group, 1996.

Quadrajet and Thermoquad mentioned but the later only used on 360, 400, and 440.

Maybe someone blew up the original and threw this engine in. Bonus for you, wish mine was 4bbl.