Remove the rockers and check the push rods for #2 & #7 to rule out the push rods being bent or out of the lifters.Shine a light in through the opening in the heads and turn the motor and watch the lobes on those cylinders.If 2 cylinders have black fouled plugs there's a reason,cam lobes,push rods,or if you're running KB107 pistons the top ring gap was too tight and snapped the top off the pistons.Since you've checked the ignition look in those areas.


77 Aspen R/T 60'@1.41 10.76 @ 123.26

http://www.youtube.com/watch?v=Eya3Ue8KoZk