On the "truck side" 3176B model(with alum. spacer), just quit(=stop production), then C-10 and C-12 were introduced(= no more 3176s in trucks for new production). I pretty much have to compare different years. This is why I stated "Semi-truck 3176"

Now, I don't know about comparing a AG 3176 model to a truck C-10 or C-12; There could be lots of similar items, I don't have any AG engine background, So I can't even guess about those.