These threads always seem to show who is a import fan and who is a V8 fan. If I was deciding between the two a 3rd gen fox body and a 240 ask yourself what you want. Do I want sound and stop light acceleration or do I want a car, with plenty of mods and tuning to be a car that can hang with Vettes without sacrificing gas mileage.
So basically I would go with a Mustang because Im biased but someone with a idea and a dream for a import due to the ability to be completely different than every other 240 on the road.
On a Mustang you still would seem like every other Stang on the road. Flowmaster exhaust Cobra R wheels and etc. A 240 could be a better DD with mods.
So what do you want? Girl attracting Stang or a car ricer wannabes are jealous of?