got some ques. re: new dash guages

[BUXMAN66]

got my new tach dash installed this w/end. some of the problems i've noticed are that the temp. guage is pegged all the way over way past "hot"....actually off the guage.my old temp. guage worked fine in my old dash. any help/ideas? also my fuel guage is reading "full", when it actually should be just below a 1/2 tank....do i need to unhook my fuel guage sending wire at my fuse box to re-set? the fuel guage was on approx. 3/8 -1/2 tank when i put the dash in so it has actually moved only a 1/2 tank of reading,as now it's on full to maybe just under. just thinking maybe the guage/sending unit needs to be reset to empty and then plugged in to the fuse box....which should bring it up to the actual amount of fuel that i really have. anybody unnerstand what i'm trying to say!?........ to back-track on the temp. guage issue,... i unhooked my wire at the engine for the temp. guage and it was still reading in the "red".......a couple of thumps on the face and on the back of the guage did bring it down some but not much.........any ideas on what happenin' here? btw...... all guages worked fine on the old dash