Water pump pulley ratio high RPM offroad

Hey there!

I have a 88 Jeep wrangler on 42s with a Mopar 360LA that has a turbo.

I have ALWAYS fought running hot while running at Silver Lake Sand Dunes in Michigan. It never gets hot at idle or driving down the road or in stop and go (its not a DD so hardly EVER happens). Regardless, it only ever gets hot (will clim past 225) from hitting the hills at wide open spinning around 5-5500 RPM. Go up the hill, down, go up another hill, go down, up another...etc. So its not one looooong duration of high RPM. Its just back to back runs.

I have a good aluminum radiator, electric fan with shroud that covers the entire rad, Flowkooler high flow mechanical water pump.

I have fought this from day one when I put this together (non turbo) 10 some years ago. I have tried various radiators, water pumps, and fan configurations. Always has done the same thing.

I JUST started looking into the water pump pulley in relation to the crank.

First off my Crank has 4 V belt ribs. So I assume this engine originally had smog pump and A/C???

The water pump pulley is SMALLER compared to the Crank. Is it possible I am just over spinning the pump causing cavitation at the high RPM? Once I just cruise around the dunes it has a chance to cool??

I see March performance sells a set of V belt pulleys for a high flow water pump that is a 1:1 ratio.

Any Ideas??