@strom Thanx,
second query, I was asking as one of my relative has a lancer supersaloon 1988-91, i don't know the exact model, and he says lancer is better then civic of same models, power windows steering, engine etc.
related to first question, if there is any way I can increase the engine power of civic, i won't go for swap, b'coz with AC on and 4 ppl in the car it move like......... turtle and with CNG you can well assume.