Are you absolutely sure you have the correct size injectors? Also may not hurt to take a degree wheel to the cam and make sure it's degreed up correctly.
Yes, the vacuum reading at idle is 14-16". On the low side. Everything I read said low vac means timing is off or a leak, but I am 100% sure there is not a leak. I tried adjusting timing with the vac gauge hooked up. The car seemed to like advanced timing of around 14-15 degrees the best.
The car does have a map sensor. I tried changing it out with a different one and it made no difference. As far as testing the map sensor all I really did was verify the 5v ref wire had the 5v. Is there a better test to try with the map sensor?
This is the reason why I understand when people ditch EFI for a carb. I will never do that, but this has me looking at the Holley Terminator X kit.