Looking for some measurements

[1988GTU]

I am looking for some measurements of the big port 3400 UIM gaskets. IIRC they should be 13.75" in length and about 2.5" width? If someone could list the exact size that would be great.

[1meanz]

are you wanting the entire length or just from the edge of one "runner" to the edge of the other? i mesured mine but i didnt mesure the tabs on each end. where the bolt goes through. it was right at 12" long, and 1 3/4" wide

[1988GTU]

[WrathOfSocrus]

The width out to the metal tab measures 2.4" using calipers and the length measure 12 13/16" with a tape on my 3500 gaskets. The outside dimensions seem to be the same as the 3400. I believe only the port size differs between the two.

[1988GTU]

Thanks.

I know a little about the different port sizes. IIRC there are 3 different port sizes? 3100 Small port, 34(1)00 big port, 3500.

[IsaacHayes]

3500 gaskets are bigger on the inside, but for the most part just like a 3400 gasket. You can cut a 3400 gasket to match the 3500 gasket. Oh, and FWIW my 3500 plenum had smaller ports than my 3400 LIM. I had more port matching to the 3400 gaskets on the 3500 plenum than then 3400 LIM took. But was easy - no runners.

[1988GTU]

Hrm so your actual gaskets for the 35 was bigger than the 34 BUT the 34 actual intake was larger in dia? That is weird.

[IsaacHayes]

3400 LIM ports compared to 3500 UIM ports, 3400 was larger. There was less material to remove to gasket match the 3400 LIM to the 3400 gasket than the 3500 UIM to the 3400 gasket.

But 3500 UIM gaskets (metal with rubber) have larger holes than a 3400 gasket stock for stock.

Hope that clears it up.

[1988GTU]

What are the measurements for the 3400 (big port) and 3500 uim gasket openings?

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[asylummotorsports]

I've got a 3500 UIM gasket here and it's, 2 1/4" X 1 1/2"

[1988GTU]

Thank you very much.