i ran a pretty tallfilled 340 block on the street,never had any trouble but then again i never had a gauge measuring the oiltemp either.used plain mineral oil also. who knows excesive heat in the oil might have killed my valvesprings alitle earlier and i lost a rollercam (not anything catastrophic, just the lifters starting to make groves in the closing ramps probably from bouncing lifter and valvefloat,wouldnt have been a problem if i had just keept a better eye on valvespring preasure and those valvesprings where far from new)due to loss of valvespringpreasure.
however it might be worse with a stroker since you have much longer piston travel making more heat further down in the bores i would suspect
im one of those that hate extra gauges they just make me nervous.