Hi Robert, I'm getting there! Just came back from cutting, burning and the start to a pad. Years ago, I built a manifold and used almost the same heat you described. Showed it to Tom who immediately said it was "minimal" and wouldn't be enough. I'd personally add another layer underneath and heat the entire bottom with water, the exhaust will heat the down tubes. Oh, I know Arkansas summers are hot but not that hot! Big Bill doesn't use any heat on his manifolds and says they run fine. You can always run 'er as is and add later if needed. I'll be down in the spring too and will be in Lavaca, I'll give a heads up when the time comes.
