Please someone correct me about this if I am wrong however you do not need to circulate exhaust heat you are just using the exhaust to transfer the heat that's why on the exhaust system heat kit I bought from Patrick's only had one pipe (copper line) going to the intake. I also believe the exhaust heats faster than the water system at start up but they basically accomplish the same thing. The goal is to keep the intake from freezing or icing.
As for me I would not want any exhaust leaks. My water systems has a blank off that bolts under the intake where I ran water in and recirculates back to the pump. I am running Fenton not Offy.
"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my sweet ride." -Amen
56 Chevy 3100 
