what are you talking about? X303's are GT40 heads... they're aluminum SVO headsTo Many Mustangs said:Just a little subjective opinion here...
I had some for sale a while back when I put AFRs on. A whole lot of people trash talked them when I was asking $300 for the fully assembled pair. The big comment was that for the same money they could have GT40 heads or used Eddies. Now I couldn't tell you one way or the other because I am no racer or master builder, but the consencus on this site was pretty overwhelming in favor of the others.
Like I said, just a subjective thought I had to share.
supercharged5.0 said:IMO... They are better then an Edelbrock performer anyday.
I made 328rwhp w/ box TW's302_plus_a_few said:I had a friend that had a set of GT40-X heads on his car and made 265rwhp. He put an out of the box set of TFS-TW heads on it and changed nothing else and made 285rwhp. It wouldn't be worth it to me to swap heads for 20rwhp but it was to him.