water temp not reading right

91 blazer 161000 miles
replaced water pump was leaking weap hole, temp sender, stat.
my gauge willnot read past 120 or so
i know it getting hot than that. any clue

when mine did that it turned out the wire came off and was reading ambient temp or something. on my 94 there are 2 sensors the one for gauge is on passenger side down between the spark plugs, the one on top center of engine was sensor for just the computer if i recall