87 si undecided?

ok i got an '87 civic si figured it would be a fun project iv been looking at what motor i should swap into it iv been reading up on the d 16 a1 browntop its a strait drop in with little modificatoin needed other that a tranny mount, but the motor is dohc which would leave little room due to the small engin bay so i was thinkin d16a6 which is sohc but i dont know what all i would have to change could yall give me some advice o ya by the way the car is currently obdo