The mod man intake looks cool but with its shorter runners it would appear to be a high RPM manifold. I thought about using one on my W5 408 but the M1 TR that's on it works just fine.
I sold a Weiand 340/360 TR awhile back to a member here or on FABO, I don't remember.
W5 408 cid, 1.324, 6.155 @ 110.34, 9.756 @ 134.67. Oh yeah, it's all Mopar too, 904 trans and an 8.75 rear!!