I'm running these exact same W5 heads on my 76 Arrow. I had W2 econo heads on my previous 72 Dart. Both ran strong. I don't understand the dislike for the W5 heads. Now I will be the first to admit that I have limited knowledge as to what the previous owner of the Arrow did to these heads. But they work well, this car is capable of hitting high 8s in the 1/4. Also, T&D and Jesel are not the only rocker arm choices for these heads. I run Harland Sharp rockers on these W5s. Perhaps not as sexy as the T&D and Jesel set ups, but a lot less money.