The VC should be tightish at start up then slacken off at working temperature then get progressively tighter at higher temperatures and lock almost solid at max temperature but what that is in farenheit on a V8 I haven't a clue.

 

195...should be lock up...me thinks

 

thanks much to all for the advice - have ordered cooling fan clutch and a/c electric condenser fan -- should be here middle of next week; will keep posted on results -- after testing per the instructions I've received here I am very confident that the cooling fan with proper lock-up operation will solve the high heat issue; thanks again to all!

 

I had some similar issues with my truck this fall... To this day my electric fan does not work as it is seized and have yet to replace it. Long story short my truck was getting into high temps very fast and I too have a new rad, and grey thermostat and so on. Turn out it was my coolant temp sensor that was running about 40 deg hotter then actual. Best way to check is to use a code reader that can view ambiant air temp and coolant sensor temp when the truck is off and cold and they should be relatively the same.

Even though my electric fan is seized (will change very shortly) I am still getting good temps according to my ultra gauge. 188 to 192 on the highway and 190 to 195 in the city.