If on a tight budget, the GT40P's are a decent performer, and if you look at Vib, green95droptop, etc they are making decent power and times with the GT40X's, but the regualr gt40 and aluminum GT40Y head are not worth the money IMHO. They are better than an E7 head, and can make decent power, but for the dollar, you're better off with a set of GT40P's or a used set of TW or edelbrock 6037's.