Recently we dyno tested 8-10 different TBI units from every manufacture. They were tested on single(Victor) and dual plane(Performer RPM) intake with wideband O2 and EGT in each Cylinder to monitor A/F. It was a ~450hp smallblock.
A/F between cylinders were all over the map with ALL the TBI units. Winners(Tq/hp) on the Single plane were the BIG Losers on the Dual plane. 1 cylinder could be 17:1 while another was running 12:1. Near 0 consistency, especially below 4000rpm. By ~5500rpm the extreme variations improved a bunch. But some TBIs were down 30-40ftlb
After seeing the results, I'll never use anything but Multiport EFI.
There's far too much variation in fuel mass delivered to each cylinder with the TBI, especially given the added variation in intake themselves. We just proved what was already known in the OEM for decades, that putting the injector as close as possible to the valve, SIGNIFICANTLY reduces the inconsistent fuel delivery