You are gonna be easily knocking on the door of 800 with just the fuel and timing change. My 93 tune puts out 745 and the E85 tune on the same setup put down 794. I was given a rule of thumb of 6-10% change in power for a given setup with higher boost and compression moving toward the 10% range.
I think mine is about 3 degrees. My setup is different from yours. I'm on a 5.8L with cams and 16psi.
id 1000's. what id get if I were you. room to grow with them for in the future.
Lots of things effect a setups MBT.
Are you tuning the car yourself?
It isn't about pressure drop. It is about unstable pressure changes at the fuel rail, due to a restriction in the return fuel line at low fuel demand conditions of the engineOne size smaller return can be tuned to run quite well. Yes there will be more of a pressure droop from light load to fully loaded, but it's not that hard to account for.
I've never played with these engines in this manner. I've played with diesel engines with a return style fuel system and the small fuel return lines with high flow fuel systems cause problems when the return isn't sized to equal or larger than the pressure supply line. Actually most of those systems we run a #6 pressure supply line with a #8 return. If I build a real high flow system it will be #8 pressure supply after the secondary high pressure pump with #8 return with a primary/auxiliary electric 260GPH transfer low pressure pump at the engine to feed the secondary high pressure pump on the engine with it own separate #8 return line. High flow for these engines is roughly around 220GPH at 120 to 135 psi. So these engines will have two # 8 return lines back to the tank. One from the engine and one from the primary/auxiliary pump. The primary pump output pressure is 17 psi to the secondary with its own pressure regulator for the return side of it. The high pressure regulator is after the fuel rail and is a gravity feed with no restriction to the tank. A standard flow system is roughly 90GPH at 90-95 psiYou've seen this first hand?
-8 feed, -6 return here. The return dumps into the factory feed outlet from the stock hat. I ran 2' of 3/8" submersible fuel line from the under side of the hat into the tank positioning it over towards the fuel tank fill. Aeration can occur from the return spraying the fuel surface in the tank right around the pumps or sump...
I'm running a glenns sumped tank with dual Pro 044 pumps run external. Very stable fuel pressure.
I wasn't disagreeing with your statement. Equal size feed & return is better than a reduction in size of the return, but real world experience has proven that a reduced size return can work.