[bobcowan]

Multiple throttle bodies is a little bit different than multiple carbs. Especially if you use a dual plane manifold, or individual runners.

Carbs draw and meter fuel primarily based on a vacuum signal. Twin carbs on a single plane manifold will draw fuel through a common plenum. The plenum will balance out the carbs, and self adjust for small variances. All the fuel gets dumped into the same plenum anyway.

EFI is different in that the injectors will squirt out the required amount of fuel regardless of vacuum signal. And the injector is down at the end of the intake runner. If you have multiple throttle bodies, it is really important that they be balanced correctly. Especially if you use a dual plane or IR manifold. That balance is critical. If you can't get it balanced, it will never run correctly, and no amount of tuning will fix that.

Balancing an 8 stack system is not all that difficult. The proper tools are cheap, and it doesn't take long. A good synchrometer is readily available, and is <$100 shipped to your door.

Synchronizing two large TB's would be a little more difficult. You can't use a vacuum signal below the TB, because it would be effected by the other TB. You would have to measure it above the TB plates. You could probably cobble together something, and adapt a Weber tool for to the bigger TB.