Does an increase in airflow (intake or exhaust runner) move peak torque up or down the RPM band?
He would have to think the Cleveland is junk too. They are all the 335 (Cleveland) family engines. The only difference is the deck height. The 400s got an especially bad rap for two reasons. 1) They were never offered with a four barrel carburetor from the factory. 2) Although Ford did all they could do, the 400 was prone to detonation. The piston was too far in the hole at TDC to take advantage of any quench, but Ford kept going the opposite direction. They kept increasing the piston dish which made the problem worse. All they had to do was put a closed chamber, two barrel head on it and bring the piston up to close to zero deck, and given it some quench. Problem solved, but they never did it.
The 351M never had that problem, because of the shorter stroke. To say that those engines were junk is a stretch at best, especially considering Ford put them in everything from the 400's introduction in 1971, until its demise in 1982. That's a lot of models and a long run for "junk". Although the 400 did have its problems, it is a fine foundation for an HP build. As long as you give it some quench and or use a camshaft with a later IVC event, you got it licked. They can be stump pullers. I have a 351M in my 75 F250 and it's hardly junk. I have a hot 400 under the work bench I plan to swap in it that's also not junk. I remember a time when people said the Chrysler 360 was a boat anchor truck motor. They were wrong, too.