Assuming you took these readings, quickly; I would expect to see t-stat/cylinder head reading and top radiator tank, basically the same, BUT sometimes it is just the surface that the gun is pointed at, can cause differences, too.

I don't like the difference between the top and bottom tank temps = too far apart. I would expect more like a 15 degree temp difference. Note: IF a radiator is restrictive(plugged, internal tubes; then coolant is slowed going downward(ie: lack of coolant flow), thus that little, small amount of coolant, going downward, actually has more temp removed=bigger temp drop(from top to bottom) BUT this is only accurrate  IF those new T-stats are FULLY OPEN; meaning the engine is truely trying to push 100% of the coolant , into the top tank, and thru the radiator.


Did you happen to get a temp reading after the water pump, but going towards the block or oil cooler?



Just reread your post, Did you aim the gun at the rubber, bottom radiator hose OR preferable to a metal area that the hose was attached to?(whether lower, metal rad. tank or metal inlet to water pump) 
Note: you should try and point to metal surfaces for temp readings, at least trying to be consistent at what you point at.