ao177snipe

I have a 73 delta 88 royale with a 350 2bbl (converted to 4bbl) and I am having trouble finding headers for the 350, so my question is will Headers for a 400 or 455 fit on a 350. Thanks in advance, the reason I am looking for headers is my factory exhaust manifolds are cracked and the mounting bolts are rusted, so I am going to be taking (slowly) the exhaust mani bolts out and praying they do NOT break or I will be having them drilled out of the heads, also any advice for that job also.