Upgrade the stock clutch fan, a 97-98 zj with the 4.0 and W/O max cooling option has a heavy duty clutch that is a direct bolt on replacement. NAPA part #272310, The standard duty clutch spins 60-70% of shaft speed. The HD spins 70-90% of shaft speed. did it on mine and went from almost going in the red in the summer going up hills to 'never' getting above 215. Makes it kinda sound like a V8 also lol.
the problem with going to a high flow pump is it moves the water to fast and doesn't let it exchange the heat out in the rad. thats why gojeep had to add a flow restrictor to get a stable temp. just my 2 cents though.