Nice Lucky you. I have to do a little grinding on mine to make fit. Ah its a project. I like the look of the Offenhauser but the Fenton's look cool too. I was hoping if I got the same intake and exhaust brand it would have saved me from the grinder. The important thing is to heat the manifold and have no leaks with water or exhaust.
Yes the heat transfer is occurring. Yup I know its weird. I guess you can think of it like a pot belly stove it radiates heat and there is not real circulation either.
good luck with it.
"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 
