Building a 273
Speaking from experience, I personally would go with a 360 Magnum crate engine. It's all done and ready to bolt in. I've got a 380HP Mopar Performance one in my one D/Dart and it is quick. It's barely streetable for my liking with the 4.10 gears The race engine in the other D/Dart is ok but I wouldn't drive it on the street. It's got 5.30 gears in it.