I run a short filled 400 block in the street for several years, just a tad above the bottom of the freezeplugs. Had no oil cooler and no oil temp gauge. And also no problems with a 3.75" stroke. I also run a RB block filled close to the tops of the freeze plugs, 4.15" stroke, no oil cooler or gauge. In that case the oil got propably too hot in continuous driving on the freeway, the oil pressure dropped after about 1/2 hour of driving from 60-70 psi to 30-40 psi level. Swithcing to synthetics made the situation better, there was even some pressure at idle. I kind of figured that as long as the fill stays below the piston ring travel, there is zero problems, and as you raise the level, the more problems. Oil cooler is definitely a good idea, and should let you use even a realtively tall fill in a streeter.