1400-1500 hours, 4.3l no rebuild, everything stock, drive the crap out of it. Most of the time it is above 4k. Actually, the only time below 4k is through the no wake zones(I had it up to 5900 in a no wake zone once though, we were seeing how high it could go!!). Oil is regular merc stuff, changed every April. Regular oil is fine. If you are making lots of power, you might make a few more ponies by switching to synthetics.