Recently got a temp' gun, and was checking stuff. I have a 292 in an F600, after a short run, at idle, I got these readings.
Manifold under carb..150 ,,I made steel inserts at the head/manifold with 3/8 holes
stock Ford 1/2" heat dam spacer..139
1 1/2" alum spacer..115
float bowl..105,,,,,,flat top 1.01 venturi
remote oil filter beside fuel pump..173
valve covers..145
.top of rad'..184,,,,temp. gauge reading inside..190
 Ram ex manifolds..250
    Comments ?

I soon found that a test in "park' was not nearly as severe as a test in "drive". The spacer on the T-birds destroys pump efficiency, and especially at minimal rpm. When the rpms drop the water barely flows - even at full t-stat opening. My car even had an original 3 blade fan, 2/3 size radiator ............ cooling system engineering wasn't a Ford strong point in 1956.

Ford's other little "warm-up" scheme is the retarded (stock) initial spark advance - and with ported vacuum from the original carb, no advance. The engine just sits there and cooks.

 
 Steve Metzger       Tucson, Arizona