you should read up on indexing the spark plugs....all the electrodes basically face the intake valves. sometimes it takes 8 or more plugs just to do a 4cyl because they all thread in different ways to different cyl.

TB spacer is a waste of money.pulleys are a ok mod on most motors. a 4pc UR set on a sr20 adds around 5-7 HP....its all about combination. a HP here and there adds up.