I have a 3.0 twin plug, 120/104 cams with 40 webers that I'm going to be swapping out for EFI. After years of running a simular system with ITB's (different engine) I'm going back to a plenum based intake.

Poor vacuum signal with ITB's is an issue, there are fixes, using a more EFI compatable cam (less duration), running alphaN (TPS only) or in alphaN with limited MAP. These fixes are fine for the race car or even the hot Saturday night hotrod, but if this is a street car, that the wife might drive, or you want to take the car on longer trips....lets just say you may not be as happy with the result of ITB's.

YMMV