I just replaced the plenum gasket on my 1998 5.9. Everything went pretty smooth except when I put the intake back on. I had a heck of a time making sure that the rear crossover gasket did not move when I set the intake in place. I dont have AC so there was a little extra room on the pax side enginne compartment. I was sitting on the wheel well in the compartment.

Its done now but I was just wondering what the gurus here do. I eventually decided it was probably all OK and I thought I could feel the gasket with my finger.

I was also wondering how I will know if it was not in place. Will it eventually be indicated by an oil leak or some other symptom

 

If it didn't seat properly it will leak oil. I would think especially on the rear because of the distributor gears and the way the motor sits. Did yours have the little **** that hold it in place?