Temperature Question

["Gronberg, John" <john.gronberg@us.landisstaefa.com>]

Facts:
Rebuilt vertical flow radiator. (new center section, "fins")
New 7 LB radiator cap
New 160 degree thermostat.
1275 engine.
Antifreeze 25%water75%.
Over the last winter I replaced the cooling components listed above.  The
two trips I have taken lately the water temperature from cold climbs
steadily to about 212F then seems to back off to 200F.  This is somewhat
warmer than I am used to seeing. Any comments. I live in the Chicago area
and it hasn't been that warm outside yet. I checked that the new cap is
holding pressure and it is.