Did you get the header thing worked? If you compare the illustrated parts breakdown between the 305 and 350. And they use the same stock exhaust manifolds and same down "Y" pipe with cat converters then it's most likely on oversight on listing " applications" the one " monkey wrench in the gears" would be if the part was not smog approved exact application. Thats why some small block parts, you know it fits, but may not be approved for install by smog regulation. Good luck.