Many '80s road frame I have actually have shorter top tubes that one might expect. I think you would be happier with a vintage mountain bike, like a specialized or trek. You can trick it out to be a great road machine with slicks, fenders, racks, different stem length, trekking bars, etc. They are bombproof and still pretty responsive. My old '90s Trek 7000ZX converted to a tourer is still one of my favorite all day rides.