Will somebody explain to me what engine, TBI chip and cam manufacturers are using to determine when an engine will or will not work with a TBI? From what I can tell, it's dependent on cam lobe separation angle which affects vacuum which then affects the MAP sensor which then can cause your TBI to work or not to work. If the cam lobe angle is too small and vacuum is lessened due to a larger valve overlap, is this the major factor that determines whether or not the TBI will work? I understand that a chip has no effect on manifold pressure and that it's all up to the cam lobe separation angle being above 110 degrees. For example, I noticed that all the cams offered by comp cams that would work with a TBI had 112 to 114 degrees lobe separation angle. Am I totally off or am I in the right direction? I don't want to waste money on a slightly larger than stock crate motor if I can't get a TBI to work.