I have my kbracing kit with a 70mm bolted to a 6.0 on my truck! I went to fast 60# injectors. It was originally a flex fuel truck, and in all my searches I find that flex fuel has bigger injectors and pump from the factory.
My question is: Can I use my stock pump to go from a comfortable .3bar, 4psi spring in my wastegate to a .5bar, 7.25psi spring without changing the fuel pump? I would love to keep that stock if possible because a get a huge discount on gm parts if anything ever happens and i hate to pull the good working pump if it will possibly work!

thanks in advance!

 

how bout ya just drive it like it is so the trans doesnt end up somewhere on the hwy and buy a fuel pump.... THEN get the spring you want, or just a controller

 

According to a knowledgeable source I spoke with, the stock flex pumps are about 250gph and the stock 38lb injectors are rated at 38lbs at 2 bar, while the 42lb injectors are rated at 42lbs at 3 bar (50% more pressure behind them), so what this guy was telling me is that the 38 flex fuels actually outflow the 42s. PM sent about source since it's a non-sponsor.

Please correct me if this information is wrong, I don't want to lead anyone astray and have them run out of fuel