A lot comes into play here as to what is "streetable" and many different opinions too. Heater,ac not plastic race seats and room for kids as you stated all play a roll. For me I love crawling over a roll bar,car shaking at stop lights,the looks on peoples faces and the gas station............face it, we love the attention or we wouldn`t be driving these things. I`m cool w/my dart the way it is and I`ve driven over an hour at a time w/out incident but roller cams,loose verts etc do need attention so it`s your call. I say big block 9.1 and turbos....