318 exhaust port differences

I gave my granddaughter a /6 74 Duster I had sitting around. I also had a 75 Dodge Dart 4dr with a 318, so she put the 318 in the duster. She wanted headers so she ordered a set of Jeg's 30080 headers. When she went to put them on, the ports were so small the gasket went below the port. So much so it would not have sealed. Just wondering if anyone has some ideas she might try to fix this? Keeping in mind she is just 16 and has limited funds. The headers and gaskets are 1.8 tall and 1.3 wide. The heads are 1.4 tall and 1' wide. In the top picture you can see light showing threw on the bottom left corner. She still has the stock manifolds, but is kinda bummed she can't use the headers.IMG_3904.jpg IMG_3906.jpg IMG_3907.jpg IMG_3908.jpg IMG_3905.jpg