SpeedMaster Heads

I have a 1970 Dart with power steering, I am currently running a 1973 340 with stock heads and Dougs D453 headers. I am going with Speed Master aluminum heads and a new set of headers. My question is will I still be able to use the same headers (D453) and still have the same clearances, or is there another brand headers with more clearance.
This is actually a great question. On a Dart I had, I went from X heads to Edelbrock RPMs and I found that the Doug's headers fit better with the X heads than the RPMs. Fitment was close, but not exactly the same. Then on my Duster with Hedman Race headers, I went from Edelbrock RPMs to Trick Flows and the RPMs actually fit a little better than with the Trick Flows. Again, fitment was close but not exactly the same. Sorry it doesn't answer your question.... lol