Car running Hot

I pulled out the stat and checked it in boiling water and it opened up fine. I got rid of the universal lower radiator hose and found a smooth one that fit with the radiator. Took it out and it still overheats. I guess my next question is how much timing affects how much the engine overheats. I have an MSD mechanical advance distributor with about 45 degrees of advance by 2500 rmp. It ran nice but now i changed out the springs so the total advance doesn't happen till about 4500 rpm. Can having too much timing advance heat up the engine.