Lately i have been driving around and all of a sudden my temp. guage will just shoot up all they way to 260 where the check guages light comes on. It will be on for a short while and then as im driving it will all of a sudden just shoot back down to normal operating temp. I dont know if its the guage or water pump or................I dont know, any insight?

H'mmmm , My 89 350 did the exact same thing a few weeks ago . Went to 240 then 190 back and forth a few time . Checked the coolant level and I checked the block at the thermostat with Temp test gun . right on 195 . Bought a temp sender and thermostat just in case ,but didn't get them put in though . Hasn't done it since . Maybe your temp sender is going bad ?