You are using the injectors in your pictures correct? EV6/USCAR connectors.
Like these?


Only way to know for sure is next time you pull one out, take note of the part number;0-280 150 081 are 25 lb/hr@ 43.5 or 28.9lb/hr@58psi or 29.4 lb/hr@60psi.

Which t-body did you use? A Vortec truck, or marine T-body. If you use a truck T-body a gasket must be used. I 1st installed it incorrectly and had a massive vaccuum leak.

Are you using the marine IAT/MAP combo sensor?

peace
Hog