Nice Duster!

My wasn't directed at you; I just threw that on here since I've got a good bit of experience w/ Stage VIs and was (am) curious where the topic goes.

FWIW, to the OP...
1. The MP Stage VI 4150 intake (RB w/o spacers) needs a LOT of work to "work", and even then has some drawbacks. It's really a poor match for your combination, especially w/ that small of a cam.

2. There is a vendor on eBarf that reproduces the MP RB intake spacers and has one (1) set left listed as of this post -> CLICK THIS

3. The "If it was mine..." answer is:
- Pull the heads, if not already off
- Get those spacers
- Have the spacers mounted to the heads & the heads' roofs raised from the top of the spacer through the intake port in a line-of-sight approach to remove the dip in the roof where the spacers match the heads
.


- Get a Victor 440 intake and do the plenum mods I've posted on here in the past (assumes you have no issue running a taller intake)
- Get a bigger cam; Hmmm... why not let Dwayne spec you a cam, too, since he just prepped your heads?

4. And what everyone else said about figuring out what your converter's stall is... But I suspect -- as long as there are no issues w/ the converter -- the current intake manifold has such a "hole" in the torque curve that it's not doing your 60-ft times any favors. You're .07 slower in the 60 and .2 slower in the 1/4 than I ran at the same MPH.

Carry on.