Your opinion:did I buy to small a radiator??

It'll be fine...if it doesnt keep it stable I'll be surprised and your issue may lay elsewhere. IMO- Run a 180 t-stat. Dont be duped into a 160, they are often times used under premonition that they will help keep an engine that much cooler...which usually arises when you think you "need" it to band-aid another issue. If your system is up to snuff, it should be fine w/ a 180 stat. 195 is just not needed, again my opinion only! :toothy3: Take it for what it's worth...but I've fought a few good "cooling issue" battle with cars...