Not w/o seriously hacking up the car to make them fit. The car was not designed for Lipo. You can get soft pack ones to fit but you may have issues with the depending on where you race. The Protek stick lipos were the only ones that fit w/o modification. There are a couple of guys locally using those in their JRXS's.
JRXS Type R, I have four of them!! ;) ( Yes, I still have them!!)