I know Stinger knows but ...
Not that this has anything to do with the issue here but ...
There's an alignment dowel on the crankshaft mount to ensure the flywheel is properly aligned. However, that dowel can be lost if it's say.... stuck to the old flywheel and the new DMF was installed without it by someone that wasn't alert.
This would probably create some timing issues but I'm not certain about that on the sixes.
So, white46m54..... what clutch did you have intalled, and did you get a new flywheel with it?