All Classified forums require a Site Supporter subscription. It is only $25 per year and you can buy and sell whatever you like on the forum. To become a Site Supporter, go to Your Profile and select "Paid Subscriptions."
Before I go searching for an exhaust or manifold gasket leak
All the old timers and the guys I worked with at Autozone, swear by kerosene. I'm thinking like 1/2 quart for a couple of minutes. BUT I'd research the procedure a little. I'd use kerosene before off the shelf stuff though. That's if you decide you want to do any of that.