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.
All that timing probably has alot to do with it.