The rims on the '85 World are 27" alloy Weinmanns, so I'm not sure it would be worth the investment to upgrade to 700c. If the bike is stock, the brakes are Chang Star sidepulls. A 700c rim has a BSD radius 4mm less than your current 27" rims (622mm diameter for 700c, 630mm diameter for 27"), so you'll need to verify the pads can be lowered 4mm in the caliper slots for the brakes to work with 700c rims. The World is an entry level bike, so only you can decide if the expense and hassle is worthwhile. Probably the easiest route to 700c is to get your LBS to simply relace your current hubs to 700c rims like Mavic Open Pros or Sun CR18s.