OK guys I admit I'm the worlds greatest procrastinator.
I bought the upgraded intake and gaskets this spring and still havn't put it on.
The car runs excellent. Thats my problem.
Should I wait for signs of failure? or do this work as a preventative measure?
Maybe those who had them fail could comment on how they let go.
All the sudden or slow leak in cooling system?
In other words What would you do based on your past experience with this failure?
I can't decide.......Prooooooooocraaaaaaastinaaaaation.

The more coolant into the engine, the more wear you get.

Frankly i'd find a free weekend and do it asap. No need to add coolant to your oil...

Definatly... not all problems are going to be visible. You have it you might as well do it now... the new part is going to make your car last a whole lot longer.

I would do it soon! I was in the exact same boat as you are with my 99. It ran excellent and gave me no reason to do it. The horror stories on BC were a strong motivator to get it done, though! My upper intake and gaskets were fine. It was the lower intake gaskets that were terrible. Take the extra 2 hours and replace your lower intake gaskets as well.

yeah... the lowers can be amazing with how bad they are - i didn't have any leaks from my upper, but the lowers were in pretty bad shape here...

I wish more people would start taking the deterioration of the lower gaskets more seriously. IMO it is the lower gaskets that are more critical to the upper intakes failing than the upper intakes themselves.

ALL POSTS ARE EXCELLENT ADVICE !! -and believe me, I speak from experience. I came very close to toasting the engine, because of lower gasket failure. I WOULD NOT WAIT ANOTHER DAY.

(-as soon as you find out, please let us all know what condition your lower gaskets were in)

I would definitely do it soon.

Some people on the board just re-torqued the lower intake and found that the bolts were loose with no problems afterward.
Could that be the cause of the gasket failure?
I don't have that high of mileage.

Just re-torque the bolts? Here is link that shows the condition of my gaskets. Now you really have me wondering if maybe it could be possible that inadequate squeeze on the gaskets could have started the whole process of deterioration. Hmmm,,, maybe. However, as you can see from the picture how bad my gaskets were, they were definitely way beyond just re-torqueing.

http://www.mike.vcn.com/bonneville/gaskets.jpg

As for me, whenever I have a Series II down for plenum replacement, I'm DARN SURE going to go that easy next step further, and replace the lower gaskets as well.

-then, maybe re-checking the torque a few months down the road would be a good idea?? Heck, I don't know. I do know that you can't get to all the bolts on the manifold, without having the plenum off, and I'd be a little spooked about tightening some, and not the others. (-I think that would really be inviting trouble)