need help with 91 civic hatch

need help i have a 91 hatch with a d15b ek3 motor and crx si tranny ive ask some friends and some say swap the motor but before i do that is there anything that can be done besides turbo to give me more horse power so that i wont have to swap it.also if swap what engine would fit better the b16 or b18 email with any info on what to do @ [email protected].

you can perform justa bout any mod out there. however building d's for high HP w/o the use of a turbo is very hard, you'll be spending 3 times the amount of money a swap would cost, its just not worth it.