Problem , Inquiry about the ECT

Hey gys and gals ,

I have a general question . I have a 1991 Fbody 302 ... Has 32,000 miles on it , its my baby . Long story short , just redid the whole coolant system , found some cracks in the fan , replaced it , then clutch , then ran it , and the Water coolant pump went bad ... So , replaced the wp , and went on my merry way... Well the other day i had HIGH pressure in my hose for some reason... ( thermostat )... long story short , i replaced it ... after " trying " rtv.. wich is a waste of time , regular gaskets work just fine ... Anyways , It was running VERY kool for the first 1-2 years i've had it ... Now , after the thermostat job I CANNOT get it to run anywhere near that...... So here's my question

1: My car was running around 135-145 ALWAYS prior , for the past year or two.. I always assumed it was hot enough , and just preffered running kool... Was it a " pinned open " thermostat that finally went bad ?

2: The car is running around the " mid " normal range , but the engine bay is VERY unsettlingly hot ... It's inbetween the A and m in Normal ... but again , this car is my baby and I treat it that way.. not a " well thats good enough " for most things....

So anyways , Does anyone know the " standard " operating tempeture for a WELL running , slightly modded pony ? 91 5.0 H.O

yo

It's 180 Thermostat , Car is running pretty much the same after warmup ... just weary b/c it used to run alot smoother in very cool temp range , but now it's more toward the " normal " range then below it ... Guess it's right , Thanks for the info though guys .