Regarding the original post - the Alco PA's were somewhat dependable -- AFTER new crankshaft support gussets were welded in to the 244 block, AND the air - cooled turbocharger was swapped out for a water - cooled model. Many early model PA's also had the entire 244A prime mover replaced with Alco's improved 244D engine in 1952. Then in 1956, when the PA's were only 8 years old, Espee upgraded and re - wired all 66 units. They were retired a few at a time through the early 1960's, the last few A - Units in 1967.
Worth noting that the Alco PA / PB produced 2000 H.P. with only ONE 16 cylinder prime mover, whereas the EMD E-7 needed TWO engines inside the carbody for the same horsepower rating, yet with less tractive effort due to Alco's use of the GE Model 752 traction motor. This HUGE traction motor also allowed for Dynamic Brakes, an option not available on any EMD E - Unit until the E-8.