well i would say do an engine swap. i dont think they would remember if thats the same engine or not.

if u got the engine swap to maybe a b16 or whatever, u could run a JDM 4-1 ITR header with the upper heatshield. it looks like stock header, and with the headsheild there, they cant tell.

for an intake, i would suggest comptechs icebox. good gains and it looks like a stock intake.

and for an exhaust, u could run something like the orginial RSR or something like that. if u can find one.