Engine won't cool off!!

here are some things i have done in the past...changed pulley diameters to speed up flow,purchased hi flow water pumps..and when i wasnt using a thermostat i made a plate to put in the water neck in place of thermostat with different hole diameters plus and minus 5/8 inch...i know they may sound odd, but it worked,and all the things listed above..timing can cause heating problems also...and the type of fan can make a difference like the number of blades and the pitch....make sure you have a good radiator,and you cant trust guages...maybe change your guage and see if it reads like the old one...one thing for sure boiling noises is bad.lol