Intake manifold gasket tips

[User_name]

Hey guys.
Since the ignition problem with my 2500 has been laid to rest I have now decided to focus on the small stuff. One of those things being the oil leaking from the front of the valley because the factory (or previous owner?) Used those stupid rubber seals on the china rails and they are popping out.
So I want to take this chance to ask a few questions regarding the tbi and it's aluminum intake.
I'm thinking of using felpro #ms93317 for gaskets, and permatex "the right stuff for chinarail sealing. What do you fellas use?

What are the torque specs for the intake bolts?

Do all of the intake bolts need thread sealer?

Is it a good plan to rebuild the throttle body while intake is off?

Any other preventative steps I can take while this is apart?

Gonna do valve cover gaskets as well while I'm there.

1995 chevrolet c2500. 5.7 tbi. Nv4500 trans 14 bolt sf g80
Once again, as always, ALL responses are appreciated!

 

[GoToGuy]

So your intake manifold is not stock. Stock is iron. And it's " Chine " not china. Use the specs called for in service manual under engine assembly. That would be your best choice, do have other reasons for not using the factory guidance? If end seals are blowing out that can also be caused by high crankcase pressure ( blowby ) or PCV is not functioning correctly. Good luck.

 

[User_name]

@i don't have blowby, or a fsm....

 

[Orpedcrow]

@User_name i believe the FSMs or some of them are in a sticky thread somewhere in here.

One tip I have for RTV is follow the manufacturer instructions. Most will call for allowing the rtv to “skin over” before assembly.

 

[PlayingWithTBI]

So your intake manifold is not stock. Stock is iron.

That's odd, my Mr Goodwrench long block came with an aluminum intake manifold, AFAIK all TBI engines came with aluminum.

As far as the gaskets, just make sure they're for TBI with the back water jacket port plates. I used ACDelco 0159409 gaskets, you're choice. Don't use those rubber gaskets on the China rails (never heard of chine - learn something new every day). Here's a pic of a good way to seal it.

You must be registered for see images attach

 

[PlayingWithTBI]

i believe the FSMs or some of them are in a sticky thread somewhere in here.

www.gmt400.com/threads/88-98-service-manuals.43575/

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

 

[packer0440]

That's odd, my Mr Goodwrench long block came with an aluminum intake manifold, AFAIK all TBI engines came with aluminum.

Most that I've seen are all cast iron, maybe some of the later TBI small blocks had aluminum. Both of my big blocks (90 & 92) are cast iron.

 

[1997]

My 95 is original and it’s aluminum.
Maybe a BB “thing”?

 

[PWC Repair]

Intake manifold bolts are usually around 30ft# give or take.
What I do with my intake bolts is clean all the holes with a q-tip and brake parts cleaner. Then I smear my bolt threads with the RTV and install them.
Rebuild the TB.....preventative maintenance goes a long way.
Maybe check/replace all vacuum lines.
What I use for RTV is the Versa-Chem "mega" line. they have black, grey, etc. I use a finger and smear it onto the clean rail surface. Also both ends of the intake manifold and around the water ports. This kind of gives you a tack coat if you will. Then a nice fat bead on those front and rear rails and assemble. This method has never let me down.

 

[Nad_Yvalhosert]

Both of my big blocks (90 & 92) are cast iron.

My '88 original 4.3 was aluminum.
The 5.0 I swapped in from an '88 2500 was aluminum.
My '89 1500 original 5.7 intake, under the Whipple, is aluminum.
My '95 5.7 is aluminum.
The lower halves of the 5.7 Vortecs on the 5.7s on my '98 Suburban 2500, and my "00 Yukon are aluminum.

I never seen a smallblock iron TBI intake. Carb intake yes, not EFI.

As for the big block, do you have an actual TBI intake or a 2bbl carb intake with a TBI adaptor?


O.P.: ditch the rubber, use RTV.