revised 3400 lower intake manifold gasket...

[FastGT31]

i plan on doing the 3400 top end swp on my 3.1. i read that there is a revised 3400 lower intake manifold gasket that doesnt leak like older ones do. what year/car did this new gasket come on? and are there any other newer stuff that i hould use?

[SappySE107]

RE: revised 3400 lower intake manifold gasket...

Any new gasket you get should have the metal tabs around the coolant passages. You should use an 00+ plenum or the 3500 plenum. Thats about all I can think of for useful info on the swap.

[geoffinbc]

Also the gasket will be ALL black. There wil be no blue or white rubber parts to it.

[v6h.o.]

Pic of the new style gasket:



you can see the two metal tabs there beside the coolant port.

[geldartb]

would you happen to have a part number for these gaskets please

[mjf1212]

new black LIM gaskets

Here's a real good write up on the gaskets:

http://www.chevytalk.org/threads/showflat.php?Cat=0&Number=795792&an=0&page=0#795792

I'd sure like to use the new gasket on my older Vin M 3100's though. Can anyone explain exactly why I can't (at least according to GM) ?

What exactly is different in the Vin J and E engines ? Is it port or bolt location and/or size or is it something surmountable (like locating tangs that could be ground off the gasket to make it fit the Vin M) ?

Also, if you could grind off some tangs and stick it in place with RTV, you'd have to go with the new torque spec too right ? I'm guessing that the torque spec has more to do with a need to compress the gasket a bit more than it does with the ability of the threads to withstand the extra torque...

MJF

[SappySE107]

Im not aware of much difference for the lower to head gaskets. The upper to lower are different size ports than the 00+ 3100 so that is why you can't use those. Lower to head should swap over as far as I am aware.

[mjf1212]

gasket kit

Im not aware of much difference for the lower to head gaskets. The upper to lower are different size ports than the 00+ 3100 so that is why you can't use those. Lower to head should swap over as far as I am aware.

I wonder if they specify only the newer engines because they sell the upper and lower intake gaskets as a kit, which in that case would make the upper to lower gaskets not fit (which i didn't know, thanks for the info).

It's really unfortunate if that's the case since nobody ever took their Vin M 3100 equipped car apart to fix the upper to lower gasket. I'll happily pay fel-pro for an upper to lower gasket (or make one) and throw GM's upper to lower gasket in the trash if I can put in a LIM gasket that will not fail again.

The part number listed in the article I linked to matches a "gasket kit" on gmpartsdirect.com. Does it generally come with the upper to lower gaskets as well as the lower to head gaskets ?

Can anyone say that they have put one of the new design LIM to head gaskets on a Vin M 3100 and been successful ? If so, what about that revised torque spec, man.

MJF

[mjf1212]

GM kit

I bought the new improved black GM gasket kit with the metal torque stops around the bolt holes. In case anyone is following this, I can now say two things for certain.

As was stated above, the UIM to LIM gaskets from the GM kit don't work on VIN M's.

The LIM to cylinder head gaskets don't work either. The locating pin hole at the top of the center intake port is slightly to the right of center on the VIN M's. On the newer VIN J heads and the new GM gasket, it is slightly to the left of center.

You would have to grind the center locating pin off of the new gasket to use it on VIN M heads. Additionally, there does appear to be a very slight port mis-allignment between the head and gasket, even if you were to grind that pin off. It's possible that you might wind up grinding all the locating pins off to locate the gasket optimally.

I think you could probably use it, but with that new metal Felpro for VIN M's, there's not much reason to chance it.

I now own 3 VIN M 3100's that can't use this kit that I've bought. If anyone of you can use it, I'll ship it priority mail to your door for the low, low price of $32.00 US.

Few bucks more outside US. Open package, obviously but a complete, and unused UIM and LIM gasket set, the part number mentioned above (89017279 new improved black GM gaskets) in this thread. All I've done with these is hold them up to the heads and see that they won't fit. Send PM.

Mike

[mjf1212]

Still have gaskets

I've still got these gaskets if anyone needs 'em.

MJF

[Rhedalert]

what do you want for a set?

[mjf1212]

Look 2 posts above.