A few years ago, I searched for a local Chevette intending to fabricate a small tractor using the drivetrain as they were powered by GM's cast iron 4 cyl. engine. Wasn't successful. It seems that Mercury Marine had bought them all up to make boat motors out of them. AKA known as the Iron Duke, they could be modified for good torque and HP. Back in the 60's, my neighbor built one using a Crosley drivetrain.
That is probably the Trenton (Today the Trenton North Engine Plant) engine plant. Back int the 1960's early 70's all they made were the 426 Hemi's and the 170, 190, & 225 slant 6's.