The S14 and S15 engines are not called blacktops... They are just called SR20's And they are alot different than the s13 SR...srslider said:It really depends on what you want! A red top is a older engine so it will be cheaper. The blacktop came in the newer S13's as in 93-97 in japan, they also came in the S14's and S15's. Of course they all vary in diffrent ways which I'm sure its been covered in this forum before.