1983 prelude huh? the car's 20 years old truthfully i wouldn't put much money into it. the motor itself is probably on its way out. i dont see it to be too logical to throw parts at a motor that is that old. if i were you and i wanted to keep the body but that old motor was giving me bad gas mileage and is that old i would get a motor like the D15B7 out of he 92-95 civic DX and LX. it has only 102hp which is suffecient for what you want and gets great gas mileage(about 34mpg city/and 40mpg highway) or go with the EX motor which will have VTEC and have about 125hp gas mileage bout the same but you'll have a little more motor to play with if you ever wanna add power. there's plenty of places to find motors on the net. i know www.ardperformance.com and click jdm engines on the top right. but go for a swap and have a better powertrain alltogether. keep me posted.