Is there any one out there that knows weather or not it would be a good idea to go ahead and port and polish the stock exhaust manifold.

 

The manifold is prone to cracking and before that porting really becomes necessary most people go single.

 

Take a good look at it right now - and decide if you want your polished manifold looking that rusty in a couple of days. It will rust, since it's cast iron.

I'm actually curious how good of a polish it would take on - I'm guessing it would never get better than a clean dull gray color.

If you're referring to the polish being a cleanup of the inside surfaces, I wouldn't expect a whole lot.

Dave