Got my first oil analysis back from Blackstone for my 2000. I'll start running them every interval now to make sure I catch any coolant in the oil since I have the dreaded 0331 head. So far so good. Curious to see how it compares to other 4.0s out there. I have slightly elevated lead, which hopefully go down in the next sample. Post your report if you've had it done. Only thing they didn't check was cholesterol!