M1 or Port-Matched LD4B on 408

OK, so you have both intakes. Changing them is only going to cost time, gaskets and beer.

Sounds like a party!
And time to experiment!
Ahhhhhh, the old fashion way of doing things, trail and error. Loved it back in the day. I still fool around with it. People ask why. I say why not. Some shake there heads.