Originally posted by firebird77clone
to diagnose a bad exhaust valve :

Have an assistant rev up the engine, then release the throttle suddenly. When the throttle is released, cover the exhaust with your hand ( obviously, don't do this with a hot exhaust ). If you have a bad exhaust valve, you will feel your hand sucked in when that cylinder hits the intake stroke. * or is that the power stroke?*

anyway.. you'll feel your hand sucked in between the exhaust strokes of the other cylinders.
If minor damage is the culprit I don't know if that would work. Also, on a V8 arent there 4cylinders firing at a time, two on either side?