Lateralus_EG

Ok Ive tried searching and im still confused as all hell. Im swapping in the b16a2 from a 99-00 si into my 93 si hb. i have the stock 99si harness and a p28 chipped with hondata s300. do i have to mod the harness at all or just plug it in at the firewall and run a new program on the ecu? I know ill prob get flamed for this one but im just so confused and i want this motor in my car already lol. I have all the mounts, radiator hoses, axles and extra fluids for everything else.