has anyone had to change out the exhaust manifold gasket on a 97 f-150 4.6. im guessing that is what the problem is. the leak seems to get better when the truck gets warmed up. and im not seeing any moisture leak from the exhaust anywhere. i guess it's about time to replace the stock exhaust. any suggestions or easy applications from anyone would be great.

 

Here's a article on header installation. The procedure covers what would be needed for a exhaust gasket or manifold.
http://www.jbaheaders.com/installshe...ml/1677_79.pdf