Shorts 330s in USAF service

I seem to remember some time ago that the USAF had acquired some Shorts 330s from commuter airlines who were phasing them out of service, because they were able to carry fully dressed P&W F100 and GE F110 engines from F15 and F16s from one base to another. Do they still use them for this purpose, or have they been replaced with C27J Spartans. How many aircraft were acquired, and where were they nominally based.