Ok, this might be a retarded question, but looking at the pics the OP posted, I don't think any of those are bike carbs. It looks to me like they are all throttle bodies since it appears as though the fuel delivery is divorced from the air metering. I haven't ever seen a carb that didn't have jet that weren't in the throats.

I'd also agree with a lot of what SiRed94 said above, and add that using a bike carb is also liekly to be much less expensive than a comparable side draft or multiple throat down draft carb setup. For example, the last time I checked a triple Weber 40DCOE setup for something like an early Z was a $1200+ expense. A bike carb setup capable of flowing the same air and fuel should cost much, much less.