Hi JT, not wishing to disagree with "Spindles" (thanks for the mention by the way
), but I have driven the Losi JRXS-Type R at our local club at a reasonable level over the last three years since it came out and have not lost a championship with it since, however, not quite sure how Spindles has got an LRP 5300 in there since I found these impossible to fit.
I run the Vampire LIPOs and have had to resort to using the 4000mah (smaller) ones since their 5200 was just simply too tall (and it is the same size as the LRP). LIPO's will fir the Type-R BUT they are a squeeze and you may well need to space the two layshaft pullies further apart for them to fit without fouling..