Did some diagnostics on the 450 today, 4 dead cylinders, 1 with slightly weak compression (but we had an issue with the compression tester and didn't double check that one) 1 with no compression (confirmed with second tester), and they all have spark. Injectors are coming out tomorrow as well as passenger side valve cover. Its tough to get much done in 3 hour increments (while Jax is at preschool). But I had 2 requests for estimates today too, neighbor stopped by and someone a few houses down from this weekends job called. Always something going on!