89 K5 with a V6

[Pookster]

it(the four banger 2.5) was called the iron duke.

i was a s10 guy for a while and thats why i know...i had a tbi 87 that ran ok but vibrated all kinds of stuff loose and got the same mileage as my 91 k5 gets.

Yeah, it was called the iron duke, commonly used in the 82+ new "GM A-Body" (the fwd cutlass cieras, buick century, etc).

The motor was a POS really. But it certainly didnt know when to quit. MY dad had 4 of those cars, the duke was better than the avaliable "v6" . We ran the engine to the ground, but it still fired up, and ran. (badly, but it ran, and didnt burn oil.) One day the cover was leaking, went to go replace it, and inside found *chunks* of buildup. Removed the chunks, replaced gasket, changed oil, and it was good for another 40k. Probably woulda still had the last one had it not been hit by another car.