Geez, Ranger. I'm sorry. I plumb forgot about our conversation and your help early on with dimensions for machining your pipe and sleeve. (But I did edit you in to the credits where I should have had you along with other helpful BC folks.)

-quick update: I installed one of Bill'* stainless steel sleeves in a new UIM this evening.
WOW It went SUPER SLICK Bill, you certainly get my "gold star award"

I hope to continue with the project tomorrow evening.

(-and just to be clear to everyone, I won't be replacing the tube in the LIM on this one, because it already has the GM reduced diameter from the factory) BUT also let me be clear, that I did "test-fit" one of Bill'* LIM tubes on my brother'* '98, and it also is TERRIFIC -in fact, actually much easier to install than sleeving the UIM. :?

And in my opinion, it is the totally best idea to do BOTH the sleeve, and the tube.

OH YES, I picked up my new GM "UIM Gasket Kit" this afternoon, (GM P/N 89017554) and guess what !! The TB Gasket is black silicone, as well as the coolant passage rings in the UIM Gasket. SURE looks to me like GM is at least TRYING to make the gaskets better now,,,, -let'* hope,,, :? And I didn't even think the list price was too bad, at $41.23. -included UIM gasket, TB gasket, and new PCV tube.

I put that on a few other Series II fourms..of course giving full credit to you bill .

Great work. You probably will help hundreds if not thousands of people understand this problem.

57ChevyThunder: You wouldn't happen to have the part number for the Lower IM gaskets, would you?

Whose lower gaskets do members here like? I've always been partial to Fel-Pro.

:? Bob, I'll post a reply this evening, with the part number(*) for the lower intake gaskets. AND, I noticed the other day that I have two different numbers there in the old garage, so I don't know what the deal is there (maybe one number was superseded by a later one??)

Anyway, the "current" numbers I have for the Victor Reintz gaskets are: Lower Intake Manifold, MS-16191A, $39.98. The Plenum Gasket (UIM), again Victor, is MS-16206, $25.87. The TB gasket, Victor, is G-31596 (-I think, not totally sure,,) for $6.64.

On the LIM, I have used a couple sets of the Victors, and one set of Fel-Pro, and honestly they look identical to me. (-for me, the Victors are more commonly available at the parts stores here in town). I did purchase one set of the GM LIM gaskets about a year ago, and there is NO WAY I'll use them -they have those stupid little cuts in the ports, just like the originals. HOPEFULLY they will come up with an improved OEM part.

I have two concerns.

1) Why take out so much original material with the reamer. Why not go with a slightly
oversize 3/4 tube?
2) This epoxy is not heat resistant enough. I've used it on exhaust pipes and it doesn't
hold up. Its great for other low heat applications. We are getting reports of the Delphi
uppers failing even with the reduced dia pipes.
Why not use a high heat thermoseal product made for exhaust for a couple bucks more
found at Auto Zone. Its resistant to 1200 deg. and claims to get stonger the more you heat it.
Just my 2 cents worth. Just finished turning a stainless nipple reduced dia 1/2 in pipe.

Bob..

I'm with Harry, I like the Felpro'* too. That'* what I have on my 99. They've been doing well since 77K (now at 110K). I haven't taken the lower off since the initial install, but when I do, I will definitely report what I find.

Bob...later this fall I will be hitting you up for a reamed upper. My upper gasket is leaking slowly, so when I go at the gasket, I'll just replace the upper with a reamed one. Furthermore, that'* when I'll remove the lower for proper cleaning and gasket inspection. The car should have 125K on it by then. Will make for a nice report.

Two reasons: First, to provide an insulating air gap between the hot pipe and the sleeve; and second, because 7/8" pipe is readily available. If your car is '95-'99, and if you are comfortable with the difference in flow you will get with a 1/2" OD pipe, you could just saw off a .820" hunk of your original 3/4" EGR pipe and glue it into your upper as a sleeve. That will give you an air gap of about .093" and a heat shield for the upper. You could even try the higher temp adhesive as yet another test!


The purpose of the epoxy is to bond the heat shield (sleeve) into the plastic upper. The epoxy is against the plastic, and it is good for 600 degrees F. The purpose of the sleeve is to reflect the heat away from the epoxy and the plastic. Hopefully, the JB weld will never see 600 F. The sleeve should be able to do that as long as the pipe doesn't touch it. That'* why the air gap is so important. It is doubtful that the plastic upper could withstand 600 F for long without deterioration, so it is difficult to see the advantage of a higher heat adhesive.

Have you heard any reports of a sleeved upper failing? The KenCo kit provides a .125 gap and a sleeve, and I haven't heard of that fix failing. Not saying they always work, but....?? We may be pushing our luck reducing the gap to .076, but it still has to be a lot better than GM'* idea of a .063 gap and NO sleeve.

The fact that Delphi uppers fail even with a reduced pipe is why you need a sleeve.

Hello ssebonne4eva -good to hear from you. And I'll be glad to share with you my "opinions/feelings" on your two questions: As far as "removing so much material", heck I don't see any problem at all with 7/8", in fact I'd be totally comfortable with a full inch. One thing to be said for removing at least 7/8, is that a person is probably better assured of removing most of the "dead/ruined" plastic, which in my mind is a good thing. (-granted, on the case of my brand new UIM, "dead" plastic is not a factor). To me, probably the greatest benefit to doing this whole modification process is creating a "comfortable amount" of air space between the EGR tube, and the plastic hole through the UIM. -WITH added benefit of heat shielding by using the sleeve. And in the case of "salvaging" used UIM'* which have already leaked, or are about cave in, then the sleeve is the ONLY WAY TO GO.

Granted, my '02 already had a reduced EGR tube, and still the same size hole in the UIM with no sleeve, and at 44k miles showed absolutely no signs of deterioration. And that brings me right back to the concept of "comfort level." What is my own comfort level? :? Man I can tell you for SURE, that every swinging unit I ever have apart is going to get a sleeve in it. And Bill'* sleeve just happens to work PERFECTLY

And for the heat factor on the sleeve, there will be essentially no heat at all on the back side of the sleeve. (from my personal experiences with heat shielding on stoves, almost all of the radiant heat will be reflected by the metal sleeve, and add in the factor of turbulant air flow in that air gap, the sleeve will probably not heat up at all.) Again, in my opinion, a person could use any kind of adhesive they want, and it won't be a problem. I even thought about using none at all, just relying on the press fit. BUT, my comfort level says that I should use something.

SO, anyway, there you have "my 2 cents worth"

I just LOVE this forum. It sure gets the 'ole gray matter actively engaged

Yes Bob, I have had nothing short of EXCELLENT results with Fel-Pro gaskets. In fact, that is always my preference on "performace related" applications. However, I'll have to admit that so far the Victor'* look just a good to me,, so far,,, :?

Great idea, I could use the original stainless pipe as a heat shield.
This forum is great for brainstorming...
As far as the reduced flow, does anyone know the consequences.
I guess GM is offering the Ken.co kit in their shops now so they must approve?
Do you think the cylinders would run hotter?
57chevy hows your car performing with the Kenco?