Yes, you can -- but the new unit must be compaible with your existing track. They are not universal. I had Juno lighting -- in appearance, the same large cans you described. Home Depot and Lowe's sell nothing compatible. But specialty lighting stores do. Take one of your old cans off and find the manufacturer and call around. Even if the replacements are more expensive than the Home Depot stuff, you will save money using your existing track. And you can DIY.
