I have recently been given an offenhauser intake and fenton headers. I hope to install them on my Chevy 261 which is bored 0.030 over with a stock cam. I do have a set of Rochester Model Bs that I plan on installing on the intake. I am assuming that I will need to rejet the carbs and possibly install lighter power valve springs. The main jets in the carbs are currently 63s; I am assuming that the springs are stock. I am not sure what size main jets and power valve springs I should use. Anybody got any recommendations?

In addition, I do plan on providing heat to the offenhauser. I am still not sure if I will be using water or exhaust heat. It seems as if water heat would be less destructive to the offenhauser intake since I am afraid that the corrosive exhaust gases would eat it up. I have the threads concerning manifold heat. I don't think that the corrosive gas issue has been addressed. I apologize if I missed it.

Thanks in advance for any advice you can offer.

Jon