I drive 6l right now and I bought it long distance on ebay ;)
But I bought it cheap enough to play with it.
Compression test on modern engines, especially diesels are huge jobs, so I usually settle for acceleration test and blowby test.
On 6l piston rings are pretty good, not so head bolts, head gaskets and EGR and oil coolers. Meaning compressor test can come perfect and you still can face $6,000 bills for new HG and new bolts.
Bulletproof oil cooler is like $1500 job.
Unless you are advanced DIY look farther.
I doubt you will find a shop who will do proper PPI on such animal for less than 4-digits.
