I think that article has a couple of errors. The "big bell" 200 didn't come out until 81 if I remember correctly, they did it because the lock up convertor to be used with the C5 wouldn't fit in the early 144,170,200 bell housing. While 351 C&W used the same pattern as a 289/302, the 351 M and 400 both had the 460 pattern. I've never seen a modular engine with the 289/302 bell housing face. I sent my senior tech to the new model course back when the modular engines were introduced and he asked the instructor whether the new engine would mate with the existing bell housings. The instructor said no and couldn't imagine why that would matter. The "interchangeable" modular engines weren't interchangeable: the Romeo 4.6 (vin code W) had 6 flywheel bolts and used different heads and valve covers than the Windsor 4.6( I forget the vin code, Ford being Ford, they used W for the Romeo). The 5.4 was based on the Windsor 4.6, which I considered to be the heavier duty of the 2. Incidentally, the Windsor 4.6's and 5.4's had only a few threads in the spark plug holes in the heads and were prone to blowing out plugs that weren't installed carefully. The light duty(in my opinion) Romeo heads had full threads.