Truck Repair: CUMMINS, hp engine, peterbuilt

Question
IS the cummins a good engine. How much does it cost to rebuild.I went to see a 90 peterbuilt with a ntc big cam cummins but the odometer went over and they do not know how many miles it has
so it os probably over a million.Do you think a dyno is dependible test.

Thank You, Anthony  

Answer
Dyno is a really good test if they check everything,like blow-by,fuel burn,fuel pressure & restriction.What HP engine or CPL?I have seen alot of engines with over a million miles on them & no overhaul ever done.The cost of an overhaul depends on what all you replace when doing it & if any machine work needs doing to the block.