JD 7710 timing and fuel 8.1 Turbo non intercooled

I own a stock 7710 w/a Denso mechanical pump. How would I go about changing the injection timing for more power and adding more fuel? I just dynoed the tractor at 157hp but I know that these engines can make up to 300+. This will not be a pulling only tractor but I wanted to play with fuel and timing to get the most out of it in stock form. I also have a straight pipe on it. Thanks for your time.

Used to have an AgBag machine with an 8.1 that was rated at 300hp. It was intercooled and I'm almost positive it had an S366. If we still had it I would try to get specs based on ESN

What is a S366?

Both Warner s300, 66mm compressor inducer