I converted my '70 Duster to Saginaw pump from a Federal and found the pressure fitting had minimal clearance to the K-frame... turns out the factory didn't install Saginaw pumps on V-8 A-bodies until 1973 when they went to the spool-type motor mounts. I was able to make it work with a really tight-bent hard line I made myself.
I didn't have any issues with clearance to the cylinder head though and I'm running Edelbrock heads on my 5.9L Magnum.
