Nope, you need 351 specific headers.
What is wrong with your 306 anyway? You might just want to supercharge it and call it a day since you already have a good deal of mods done. If you were going from scratch I'd say go 351 though.
2000 Mustang GT Steeda #0048
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.