These are some small mods you can do to your 2s-e celica to make it more fun to drive There comes a point when you would be better off swapping a 3sge in because its a much better engie design Intake-you need to design your own. cold air intake with a pod filter(larger area) is the best design due to the fact that its away from the heat created by the engine but you can get the same effect on a short ram intake by heat shielding the pod filter. a smaller exhaust-no exhausts aftermarket ones available so you have to design your own. The stock 2se is ridicoulsly small it would be a good boost just to go upgrade to the stock gts. For designing your own go for around 2.25" and acoomadate a muffler/resonator to your liking cylinder head-I have absoultly no idea what you can do besides regrinding your stock cam. You might be able to use performance 22r valve springs and retainers but i have no experience with this. If you can find mechanical lifters out of a 1s or 2s-c this would be a great upgrade if your going to regrind your cam.