if that engine hits that temp at idle, either your low speed needle is too lean, or your idle is set to high. if your engine is trying to'lurch' forward, without the brakes engaged, the idle is too high.in other words, if you have to hit the brakes to keep the truck from rolling away, your idle is to high.

when tuning, always tune the high speed needle first. do several high speed passes after the engine has warmed up, and take a look at the temp. with an engine that big, it shouldnt get any warmer that 220 to 230 deg.

i tune my low end a little different from most. if im not satisfied with the engines of the line punch, i will make small 1/8 turn adjustments until the engines acceleration is acceptable. then ill bring the truck over, and let it idle, while constantly monitoring the engines temp. if the temp goes up while it idles, the engine is to lean, if the temp goes down slowly, its right on. hope this helps.