Jim..You ever pull the nozzles off the twin and pour the plastic in directly from the cups? I know it's dangerous, I do it now with a single injector.
NEVER. How could you hold the twinjector up (safely) and then put the nozzles in. Way to much manipulation in my opinion. The plastic will be cooling all the time you are doing all this.
Other big thing would be all the bubbles will rise up to the tips of the injectors, just the opposite of how you want it.
It is just so easy to suck the plastic up and then inject it, I can't see it doing any other way.
Jim