size of early MFI intakes - are E and S different?

[RichMason]

I've searched the archives and I haven't found a definative answer to this. I have procured a set of S TBs and magnesium intakes for my RS project. The S TBs are larger than my E tbs at the bottom (36mm), as they should be. However, the tops of the TBs and the tops and bottoms of the intakes are the same size on the E and the supposed S setup. Was there only one early magnesium intake setup that was used for both engines? Further more, will this size intake be appropriate for a 2.7 RS MFI set-up?

Thanks,

[724doorE]

Good question, I'd like to know as well!

[Chuck Miller]

Matt will know for sure...


Eurometrix

228 Boston Rd.
P.O. Box 879
Groton, MA 01450

Tel: (978) 448 2557
Fax: (978) 448 0335

[Tyson Schmidt]

From what I've seen, the magnesium intake stacks were all the same, but the throttle bodies were different.

The plastice ones from '72-on were all completely different for T, E, and S though.

Also, the '69 intake stacks are different stud spacing at the bottom, and will not fit the '70 and later T-bodies. The '69 S mag stacks are a little larger at the top than the later ones as well.

[Scott Clarke]

Rich-
As you note, the tops of the TBs are the same in both E and S components. the throttle plates are the same diameter, as well. There is a difference in the stacks, however. An E stack has a diameter at the bottom end that is smaller than the upper diameter of the TB, leaving a "step." I believe that the upper stack diameter is allso larger on an S stack, and that the upper diameter of a '69 S stack was larger still. So, to convert an E to an S requires enlarging the lower poriton of the TB, and increasing the inside diameter of the stacks for their entire length.
-Scott

[RichMason]

No steps anywhere as both are a perfect fit on either set of TBs. Hmmm... Sounds like I may need some machine work for the RS. Anyone have any recommended dimensions for boring these out for such an application? The later intakes are misleading as guides, as I understand it, because the velocity stack is built into the intake.

[Scott Clarke]

Rich-
I've got my mag stacks in front of me ('70E). Top is 38mm, bottom is 36mm. Bottom of TBs is 32mm, top is 38mm BUT these were just rebuilt by Eurometrix, and as a result have throttle plates that are 1mm oversized. I'd be interested to hear how these compare with S specs.
-Scott

[mackgoo]

Find the upper diameter of the plastic "S" stacks and copy that. That is what was in the RS.

[fryardds]

I'll second what Chuck said, call Matt Blast at Eurometrix. He is the guy that will give you all the details about what you need to do and he is the guy to do it. It will take awhile for him to complete the job, but it is well worth the wait.

[RichMason]

From Matt at Eurometrix - The early E stacks had a smaller tapered bore than the S stacks. The bottom of an E is roughly 35mm and the bottom of the S stack was roughly 38mm and came close to matching the top of the TB. The E and S were both larger at the top than at the bottom(tapered). The '69S is kind of unique and the most desirable for your appliation because it is even larger at the top(about 45mm) than any other stack(later RS included). I'm not sure what it would show on a dyno but they are somewhat rare and they look good. The '70-'71 S stacks were a few mm smaller on top but tapered to the same 38mm on the bottom.

I would measure the top and bottom. Is it possible that you had S stacks on your E TB's? Ideally you want 38mm on the bottom and about 43-45mm on to. If they are 45mm on top then they are '69S and you should be happy. Matt

[RichMason]

So it ends up that I had 69 E TBs with 69 S intakes on my car. The set I ordered are indeed 69 S TBs but he sent me one S intake and one E or T intake. Pays to buy a set of calipers and verify your purchases.