Check your jetting and your idle mixture. Put 78-80s' in the primaries, 80's in the secondaries(if you have a holley double pumper, and you should)
If the tranny's input shaft is being shoved into the back of the crankshaft, the motor will have excessive thrust bearing load, wear, and heat buildup. Pull the tranny out of the bellhousing, measure the distance from the rear bellhousing flange (where the trans bolts on) ,to the pilot bearing, as installed on the motor. A straight edge and a piece of welding rod and a magic marker works fine. Compare this distance to the tranny's input shaft length. The input shaft needs to be inside the pilot bearing 1/2" but cannot be allowed to bottom out on the crankshft. 110 degree
oil temp in a SPF is hot unless you're running at over 4500 rpm, with low speeds (no airflow thru cooler). The 500 hp 351 strokers (418 cid) usually run 80-100 with spirited driving.
If the motor is brand new, they do run hotter while breaking in. (But the water usually heats up before the
oil. If the
oil gets hot before the water: a problem. ) Just shut it down after the oil gets to 100, wait for it to cool, and heat cycle it twice more. By then the rings should have seated, and it should spin easier.