Leak Down results

Thought I'd finally bring myself to do a leak down test on the motor and see where things lay. I have always suspected at least 1 dud cylinder at least because of an inherent vacuum tick at idle that persisted even after heads were changed ruling out valves.

1. 10% 2. 15%
3. 12% 4. 12%
5. 15% 6. 15%
7. 10% 8. 45%

Still managed to run a 12.6 @ 107 MPH. Any takers on what the poor ring seal was costing me?

The rebuild has begun with another block dropped off at the machinists and a set of unused second hand KB107's most likely.