Isn't the 153 just a 230 with 2 rear cylinders missing. I looked at the layout and from the top of the block the 153 looks like the 230/250 with the last 2 cylinders not cast.
I'm getting the 153 plate from a forklift shop. Evidently the 153 was a pretty popular engine for that vertical market. I have the head off one of my 292s and I can throw it on there and see if there are any irregularities?!
