My 340 is pretty much the same as you describe yours, including the .590 cam. I did no oiling mods on mine and it has been running for 6 years, although not as much time on it as I would like simply because I haven't been in a position to put a bunch of rounds on it . It had seen 8000rpm trying to figure out what it liked but didn't want to short live the motor. To be fair, I highly regard many members here and Mr. P has given me valuable advice in the past. His, and many others, council has been very welcome. Good luck on yours!