what specs are you looking for?
i have no experience with the GYT mechanical fuel injection set up. those who knew how to set them up had very fast sleds!
i have been using strictly 44mm round slide mikunis with Aaen race pipes.
from what i hear, the 40mm throttle bodies are the hot set up for the gyt 340 and the 42mm bodies for the 440 gyt srx.