Radiator issues (maybe?)

[Spline64]

Thanks guys, zac you were correct, the top hose got hot after driving a few miles. Heater works better then ever (probably cause the t-stat is now 15 deg higher). Engine even runs better now, guess it was never reaching optimum operating temperature.
Eyebuzz, I did put it in boiling water and it only opened up less than a 1/16". Couldn't even push it open with my thumbs beyond that. The new one would let me push it over a half inch open.
Amazing that a $4 part could ruin a $1000 engine.....getting the temp gauge this weekend. If that was working I wouldn't of almost ruined the engine

again, thanks!!
Spline64