This post has been dead for a while, but I wanted to add some insight based on my experiences as I have a similar set up.
I have 11:1 JE Pistons and Manley rods. Not sure the bore, as i actually bought this motor as a "stock replacement", i'm not sure the back story why he didn't admit it was built . . . maybe because it has the cold forged aluminum piston knock and he though he was selling a motor with a bad bearing. Anyway, i bought it, and its been running fine.
Other than pistons/rods, the motor appears stock from what i can tell (stock valve train etc).
I installed the upgraded oil pump, long tube headers, 47lb injectors, upgraded drop in fuel pump. I have done all the tuning myself.
What i can say is at 11.1:1, it will run on 93 octane. It didn't feel fast, it was quicker than the stock motor that came in the truck when i bought it, but it wasn't impressive.
I can say if you are only running 93 octane, the benefit of 11:1 compression on these motors isn't great. I had to pull some timing to keep it out of knock, so the motor always felt a little soft, even when running at the edge of knock.
I was running 93 until i could get a solid base tune dialed in. Once i finished the 93 octane tuning, i moved over to E85. Now, with E85 the truck is pretty darn quick! The ability to add timing back into the system has significantly increase the snappiness of the motor. It is super fun to drive now and definitely feels like it has a performance motor.
I was getting about 12mpg with the built motor, i lost a little mpg going to the 11:1 compression which i believe is due to the lost timing. Going to E85 i've not really seen a change in MPG . .. while one would generally expect to see about a 20ish percent drop . . . I believe the engine has offset this with increased efficiency by the added timing.
If you have access to E85 and can tune the motor to run on E85, the increase compression is definately worth it.
I still think a SuperCharger would make more power . . . but at the level of timing i'm running now, i could probably add a few pounds if i wanted.
Just some notes for anyone in the future who is thinking about a NA 6.2 build. I'm not going to dyo the truck, there is no value in it for me, but based on the many fast cars/trucks i've had, i'd imagine my setup has me in the low 400 RWHP . . . i'd imagine i picked up about 50RWHP when i changed to E85 and got the tune dialed in.
Note: i'm actually tuned "Flex Fuel" so i can run 93 if i can't find E85 . . . i would definitely go that route if you want to set up to run ethanol.