My mother-in-law'* -1 GP GT just had an upper intake failure. I thought that it would have the better intake, and so did the dealer. They replaced it for free. Oil looked fine, I think they changed it anyway.

IMO the intakes are all going to experience the same thing. I think we haven't seen enough age and mileage yet to see the manifestation.

And even more important...I think the lower intake gaskets are still not improved enough yet to prove reliable.

My thoughts on this have been that they last 5-7 years typically w/o a problem. What is the expected life of a vehicle from the manufacturer?...

Sorry to get off topic... Merely trying to say that GM probably didn't change the design much if at all and didn't think it was a problem because of expected service life.

bingo!

That'* pretty much it, in a nutshell. Improvements made to the EGR stovepipe will make 00'* (and late 99'*) last longer, but it never really 'fixed' the problem. the upper itself never changed.

as for the lowers, there've been two updates in the last year and a half, first to put metal sleeves in, and the second (though I haven't seen them myself) made the entire gasket carrier metal.