Space isn't that limited on the J-10. I remember a Chinese language report saying that a radar the size you can fit on the F-7MF has a theoritical maximum detect range of 160km.
you better double check again, the Chinese website tend to be not reliable.
huitong claim of 120km range, Israel FAST radar design to retrofit older APG-66 claim to possess 130km range.according to israel AF personel,FAST radar possess far better air to ground mapping capability than Apg-68 V-9.
unless,there's is possibility that KLj-1473 raar may have based on israel design.