you mean base model vs the type s model? base model is k20a3.. its for fuel economy.. it has 5 gear ratios for the transmission. when you engage in vtec its not that must improvement.. the cam lobes are not made for higher lift. the manifold is for daily driving and saving gas.. headers are different.. now the type S is made for racing.. I have a k20a2 or type s motor right now in y 97 civic hatch.. its amazing! just go with type s man.. you wont regret it.. plus it responds better to bolt ons like air intake, manifold, headers, etc..