Sounds like a great car; if it were just the rear banks, or just #8, I'd say your heads had blocked EGR ports (#8 normally plugs up last -- very common); however, first and last cylinders is probably normal, or possible slightly leaky cold start injector, as the idle air bypass w/ cold start injector start at each banks middle cylinders and work towards the outside of them. Could also possibly be a leaky fuel distributor; you can verify this by checking out the lower fuel distributor housing (push down the airflow meter and see if you detect any "wetness" on the boot or around the throttle valve). There are more even remote possibilities, but you can check these if you like.

__________________
Don't ask me, I'm a shop-owner by default