WILL A BA BF AIR BO ETC FIT INTO AN AU??
I have been told it will but with a bit of modification?
Does anyone on here know what that entails at all?

Well if like the e series, it requires an Irish shifter, and a few well located swings.

Massage if you will of the inner guard, plus pop out the spacer rubbers grommet things and pop in the au ones.
Also use the ba piping from air-box to throttle-body, is what people generally do.
can get around it but easiest.