The
exhaust backpressure is supposed to be between 1.0 and 1.5 p.s.i. I'm not sure about hte water presure, but I'd think it wouldn't be that great. Try the J.B. Weld, along with replacing the hot section of your
exhaust. You can pick up the black iron pipe for this at Home Depot for about $25. If the J.B. Weld doesn't work, you'll be buying a new exhaust manifold from Moyer for about $350. All the attendant parts, such as the exhaust flange and heat wrap, will run you about $450 with shipping.