Temporary exhaust system
If you have stock exhaust run it until you have the $$$ to change it.
If you were just breaking in the cam and didnt have any exhaust I have used manifolds and about 1' of pipe for the break in. For the exhaust system try the summit/jegs system with the house brand headers- you can't beat a complete header/exhaust set up for under $300, it's even mandrel bent and aluminized.