like new M1 FOR S/B

This is how it was explained in a thread on Moparts:

"P4452893 is actually the casting number.......for 2 different intakes.

The P4529460 was machined to fit the raised ports of the W-5 head.

The P4452891 was machined to fit the factory LA heads, Edelbrock,
Indybrock, Brodix B1-BA, Small Port Commando.

If you have an intake with P4452893 on it and the bolt spacing
matches your heads, it will work."