Does a Rosy Boa absolutely have to have belly heat?

The title says it all. He has a great heat gradient 87 to 90 on the warm side and 77 to 80 on the cool side. Just wondering if he needs belly heat, too. He's only had intermitant belly heat for a few days (turned it on briefly and off again b/c otherwise it gets too hot). Now, this is more of a curiosity question, since my husband put the dimmer on the source of belly heat (a 100 watt foot warmer :D). We just need to get the temp of the belly heat right with the dimmer. Thanks!

No.. if the temps are correct, it doesn't matter if it's belly heat, or an ambient temperature. Many of my snakes are in racks with back heat and they do great.