I'm interested in purchasing these heads for my sbc 350.They are dart....Are they worth what the guy wants for them?Thanks bm http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7919883133&category=33617 Opinions ,advice?Money better spent somewhere else??I have stock cast iron heads that came with the 94 gm crate motor.thanks bm