170 psi says it has plenty of compression to run. For instance, 3 cylinders showing 50 psi would indicate a problem. The engine came with remanufactured heads, I'm sure, which included new valve springs. Not high performance valve springs, just new replacement springs is how parts store motors would most likely build it. I'm really doubtful valve springs are the issue here. Again, I've shared about all the info I have on the motor. I did not buy it new, it was from craigslist. I just took enough of it apart to verify it was new.
