Another overheating situation 63 Slant six

No stat will cause it to possible run cold (no time to cool in the radiator) , increasing cylinder wear. You want it to be about 180-185 for maximum driveability and minimal cylinder wear. take rad out and tape up the bottom feed. fill with 33% (1:2 acid to water in that order) pool acid for 5 minutes . Drain somewhere it wont etch, ie another bucket. flush out with fresh water hose for another 5 minutes. RUN A STAT! Can do the same with the block but its easier when its all buttoned up with some block flush and some engine heat. Pushers are always 2nd rate compared to pullers on a car and a shroud (any) will help with a puller. Even a very shallow one as long as it covers the entire radiator and makes the puller pull air across the entire core. your pusher at idle is only really affecting the area of the fans diameter.