dont get the thermostat , itll make it run cooler yes , but if it never reaches operating temp , the comp will keep thinking it still needs to add more fuel to warm it up faster , all youll do is burn gas , and it wont run its best on 87...itll run the same unless you do play with the fuel and spark cruves and timing , at which point you will need to put it higher octane to keep it from pinging , but putting in high octane (unless recommended by the manufacturer) has absolutly no point