[Pegdrgr]

Even with 6 550 injectors you are not going to be able to keep up with a GT40 turbo, same story with the Walbro. You can go with either 2 Walbro pumps, or move over to a more stout pump like the Fuelab 41401 or the Aeromotive A1000. Either of those will keep up with the fuel requirements of what you are contemplating. The Aeromotive has the limitation of 70 psi, which means you can't run more than 30 psi boost, although that is not likely to be an issue for you. I do like that the Fuelab has a built in PWM controller, so you can throttle it back while cruising to add to the pump life and reduce heating of the fuel. There is a guy selling a new Fuelab on NASIOC right now for just over 300 shipped. 2 Walbro pumps are cheaper than either of those options, but you will loose your motor if one of the two pumps fails.

While the gear ratio of the 5 speed is typically preferred to the 6 speed the differentials in the 6 speed more than make up for that if you are looking to the 07 STi transmission. There is no doubt that the PPGs are nice gears, but they cost as much as a 6 speed, and if you add in the price of differentials on the 5 speed to make them as effective as the 6 speed ones you are talking several thousand dollars more. Finally, if you are going to have someone install the PPG gears strongly consider Andrewtech as they know the PPG gears better than anyone in the US.

Good luck with the project, those will be 2 incredible machines if you plan it out well!

Jarrad