GM throttle bodies are a low pressure affair, 12-15 psi. for fuel. The people who have done this before say one needs to maintain 5 to 6 psi above boost pressure...requiring an adjustable fuel pressure regulator that responds to boost. stands to reason since they were originally a vacuum based system. TBI fuel regulators are integral within the unit. I don't want to go there on my project. Seems like a number of us are dealing with this right now. Good luck. PS.. lots of info on other threads here..
