Hi... I have an L36 k vin 3800 series 2 in my 04 Monte.
Had the upper intake go out and since I was almost there I decided to do head gaskets 150000 miles on my motor.
I got a complete gasket kit did the valve seals didn't notice any difference when I installed them. Now the car smokes especially when sitting a long time idling. Also uses almost a quart every 2000 miles.
I looked up the gm part numbers and it shows 2 different part #'s for the valve seals one for exhaust and one for intake.
I also lost about 3 mpg. Are the seals the same or different? Didn't get a valve job but car didn't smoke before and got 28-30mpg before disassembly.
What should I check or redo?