Isuzu Carburetors
Isuzu applications used a variety of  two barrel "down draft" style carburetors from both Hitachi and Nikki. 

The 1981 I-Mark & Pup models used the same carburetor as the 1981 Chevy Luv pickup truck. However, beginning in 1982, Hitachi was building carburetors specifically for the Amigo, Trooper II, I-Mark, and pickup truck applications.
 
In 1985 through 1989, the I-Mark   switched to a Nikki two barrel carburetor. These are identical to the Nikki carburetors used by Chevrolet / GEO in the Spectrum applications.