Not a bad read BUT they need fact checking. From the D 35 they had wide and narrow models. It did not start with the 8u and 9u. I am not 100% sure but I thought the D6 B had a newer engine than a D318 like the u series.
The D6B had a333 engine nice tractor I loved it, I had a wide gauge RD6 I have seen wide 40s. My first 6 cyl. D6 4R had I think a D4600 engine was ALOT different than D318 and not just bigger sleeves and pistons. Whoever wrote that article had no idea what he was talking about! 17afarmer