Pre-purchase checklist
 

Got a prospect on an '86 F250 4x4, 6.9 with a transplanted ZF5. We've been around our PSDs enough, and the 300 in an old '83 F150, but no familiarity with the 6.9. What should we look for when looking at the truck?

You can do a compression test from the "outside" on this engine, right? Is it hard to do?