Hey guys, I have a 1974 (I think) Grand Prix. I was wondering what the frame is made of ? I don't think its Reynolds 531. If not 531, whats the difference ? Is it weight? If so, how much heavier would my frame be than a frame made from 531 ? Their was a decal on the seat tube but its gone. I think this told the frame material.

Here is a link to an earlier post where I posted pics of the bike.
http://www.bikeforums.net/showthread...ght=prix+grand