Well, I finally got around to doing the intake gasket job today. I am glad it is finished. Not too bad but a little time consuming. Everything appears to be ok, we drove out to dinner and the mall, nothing unusual happened. Now, I do have one question though, just how dirty should the intake be? What kind of fluids pass through and where? Maybe I just do not understand the purpose and operation of the intake....I thought mine was really grundgy but maybe it looked like it should after 143,000 miles.......I did clean the throttle body, it had some serious carbon build up on the intake side of it.......Thanks for all the info and encouragement......any answers for above..........thanks

I replaced mine at 160,000 miles and it wasn't bad at all . But, i'm sure the previous owner use premium octane fuel!

Purpose and operation of the intake is to deliver an air/fuel mixture to each cylinder. It is sometimes used to deliver coolant between water jackets and to allow unburnt exhaust gasses tyo be routed back through the combustion chamber for efficiency. Using a top quality fuel in the highest octane available will help reduce carbon build up.