With some adventuring in local junkyards and the advice/wisdom of willwren, I am attempting to install a 92 aluminum upper intake onto my 94. This way I eliminate the possibility of warping a plastic intake and doing maybe even worse with sudden temperature changes due to nitrous. According to willwren its best to just block off the coolent passage to the TB which I could get all technical about, but it hurts my head. Bill can explain all that.

I'm just hoping the 92 and 94 lower intakes are identical, if not I may go grab a lower intake off a 92 L27 and see what can be done. Sadly this does not pertain to L36 drivers because of a much different intake system (just by comparing the L27 and L36 runners you can tell something doesn't quite match).

Also I will have to get the upper intake matched to my 94 TB because the 92 TB was slightly smaller and a custom gasket will have to be made by my retarded self. :?

In conclusion, if this all works out I believe it will be a breakthrough for us L27 plastic upper intake owners.

This'll be cool. There'* two of you working on it now. Deathrat, can you confirm that the 92 and 94 lower intakes are the same part number? We're concerned about the location of the PCV passage.

The other unknown is the gasket for the TB, which will have to be custom made.

This also opens the door of possibilities for PORTING the UPPER intake. Imagine!

And porting the lower intake while we're at it.

I'm working on it, but it'* gonna take a little time for me as we're moving our Dealership across town right now, in fact today at noon we shut down & finish packing so we can open Monday morning in our giant new home!

In that light though, the 92 Lower Intake is P/N: 24500779
I can tell you though that GM will say that they're different due to the TB size! Whether they match up on the lower end to the heads though, you'll have to go pull one & compare it. That way you'll know if all the coolant holes, etc line up.

If I must, I'll pull a 92 lower intake...which HAS to match up!

Today I finally got the TB off and started cleaning the upper intake. Only issue I know I have to deal with is getting the upper intake to match the size of a 94 TB. Anyone know the bore of each year? (92 and 94)

Don't forget the sealant between the upper and lower manifolds.