I too have found the factory settings on this engine to be way too lean. You have to remember that you adjust your engine's tune to your environment. I truly think your engine is fine it is just too lean on the low end. The way the temps rise on these engines is nuts because of how tight they are. You do have to run them rich ( but not fuel spitting slobbering rich) or the temps will climb fast. The good news is that once you stick it out and get her fully broke-in the engine runs great and will last a long time. I have about 9 gallons on mine and she runs like a top, I race with my 454. I also changed the bearings out at the 6 gallon mark.