Common Procomp crosswind intake manifold problem.

Bakerlite said
Guess they fit the Magnum better than the LA. But as you can see this manifold is on LA,s, not Magnums.

As far as I know and seen, the angle of the head to intake relation is the same. Attaching screws points/angles are different.

65Val said
Not a theory....Fact: the early heads have different bolt size and angle...looks just like whats going on here.

While true, the issue would be actual size of attaching screw. The earlier 273 engines used a smaller attaching screw so the newer ones will not even attach.