Scored this today. I'm guessing mid/late 80s GT. Sticker on seat tube says Huntington Beach, but that doesnt mean it is. Not sure if the blue paint is original, but it's a real good paint job if it's a repaint. GT forks, chainwheel, seat post clamp, and seat post looks like it had a GT sticker on it at one time. The bike also has aluminum Powerlite powerbend bars, DK stem,GT grips (that say "made in usa"),Dia-Compe MX1 brake with the Weinmann semi automatic adjuster and alloy wheels with old school ACS hubs. Anyone know GT serial numbers, or where I can find them? The serial number is on the left rear dropout.