FWIW, my QH on the J4J1 for my vortech 302 has been very good. Tuned by Willie Lynch and car makes low 400 to the wheels and nice and safe so far. I do worry about my tuning becoming obsolete.Has me rethinking my plan for my 347& vortech.. Originally planned on quarter horse & leech.... Then changed to termX when those both became unavailable... Now I'm not sure what to do