Headers for 318 Duster w/ p/s

We have a '74 Duster with a 318 that we are getting ready to start building up. The car is all original so we decided to build the 318 and 904 rather than swapping them out. I have been looking for headers for this set up and it appears that most of them indicate that they can be used only on cars without power steering. I don't want to give up the power steering if possible. Does somebody make a set of header for a 318 Duster with power steering? Thanks