Mopar Stage VI Intakes???

Anyone have any experience with the Mopar Stage VI specific intakes that are made by Mopar Performance. I'm speaking of the P5249358, which appears to be for an "RB" with the taller StageVI heads, so it would be wider than a standard RB intake as cast. They don't look very tall, just don't see any discussion on these, if ever.

Got a set of ported Stage VI's and like the idea of the cast valley cover that is integral.

The P4876128 & P4876129 appear to be Max Wedge. I'm wondering if I could open up the standard port P5249358 to Max Wedge later??

I had a RB Stage VI combo and I used the 4500 intake SVI specific intake. My ports were a bit larger than stock, but not max wedge. I port matched the intake and blended about 4-5" up into the runners. Can't say if there was enough meat to go max wedge or not.

OK, Thanks!

I know your combo ran well for you back when you had that J-body. This set-up may end up in a 80 Cordoba as well.

Just curious would I be better suited to start with a 4500 style manifold and adapt to a 4150 to play with carbs or the other way around. I know some guys prefer the smaller opening, adapted to the 4500, on the Indy manifolds. Dunno if this would be relevant. Hood clearance is not an issue.

For years I ran the spacers and a 4150 RB M1 intake topped with an annular booster 850 carb. The car always launched like gangbusters, but on test runs it always seemed a large number of cars would pull me on the top end. We even changed from a 4.10 gear to a .56 to see if it would help. I ended up buying the Stage VI M1 and an old Carb Shop prepped 1050 from a guy off of Ebay. Car instantly picked up 4-5 mph, and I went from trapping at 6000-6200 to right around 7000-7200. That scared the crap out of me with all the stock stuff I was running so we went back to the 4.10 and the car picked up even more, at a much lower rpm. Obviously im my case the 850 carb combo was the cork in my induction choice. My head flow numbers are in the stage vi archives and I was running the old tried and true Ultradyne NF-69 cam .640 lift.

I do still have the RB M1 and spacers if you are looking for something to play with.

Dean, I just machined my 4150 flanged M/W Stage VI intake for 4500 carb. Installed it yesterday or I would get pictures of heads and carb flange. My heads were not M/W but intake openings were machined to M/W specs. I would get the 4500 flange and adapt for the 4150, I wanted to be able to use either carb, and don't have the hood clearance for the 4500 adapter on top of the 4150 intake. Now, with machining, I can use 1.5" spacer for 4500, or re-machined 4150 to 4500 adapter @ 1.7" and have adequate clearance. I removed 1" from the intake when converting it to 4500. Wish I could tell you how it runs but I won't know for another couple weeks if this weather ever get good enough. I'm hoping for 9.60's and 138 mph...

Before maching carb flange.

I'll try to be brief from mine and other's experiences I can pass on:
1. The out-of-the-box 4150 version w/ standard-size port sucks on a 440-type combo.
2. With a LOT of plenum rework and runner porting, the 4150 version w/ standard-size port made very good peak HP, but had a big hole in the torque curve under 4000 RPM because the plenum is BIG.
3. The out-of-the-box 4500 version could use some plenum cleanup & blending, but is a better piece than the 4150.
4. These intakes are designed as Max Wedge-sized, regardless of the runner exit sizes as cast, and seem better suited to MW ports on 500" combinations.

Carry on.

Brad, are there any pix of the plenum work you've done?

I can believe the torque comments. I had my shift light set around 5600 and would trap just a bit over 6k. Pretty boring ride compared to running my dads W5 Duster!

Quote:

---

Brad, are there any pix of the plenum work you've done?

---

Yes (the work on that particular intake was actually done by Roger Helgesen), but I can't locate them since we had to rebuild the 'puter on which I used store my images.

The best description is that a LOT of work was done under the area where the carb mounts to add a nice radius into the roofs of the intake runners, unlike the severe & abrupt change in direction that's required in as-cast form.