I would say those are really good compression readings..I had the same high reading on my back 2 cylinders at 250k..I did have a blown head gasket between 1 and 2 so that reading was half of what it should be..Cylinders were swapping pressure...When the motor came apart there was only a bit of carbon on the top of pistons..Even the exhaust valves were clean..Found very little carbon anywhere..I was amazed..I have done some water cleaning through the intake in the past and that may have helped..