340 X heads and Doug's D453 headers

Hi All,

Bought Dougs 447D453 headers for the 273 in our 67 Barracuda.

https://shop.dougsheaders.com/doug-...-coating.html#product_tabs_description_tabbed

Then came across a 340 with X heads to buy. I was told that the port shape may be different. New to small block Mopars, will I have a problem with port matching or installing the headers in general? Thanks!
I have a 68 340 with x heads and Doug headers greatest headers I’ve ever ran on a 340!