Yeah. Im running long tube stepped TTI’s to H pipe, 2.5 full system out the back, spiral core mufflers before axel bend in my 72 Duster with a 340, 4 speed w/ gear vendor, 73 up drag link, manual steering, 90* oil adapter w/ wix 51051R which is large, and car riding low. There was no clearance issues at all at any of the points. The one spot that I had issues was my old drive way was peaked where the sidewalk met the flat of the driveway, would scrape the the H pipe ever so slightly. I’ll post a pic in a little while.
Now a buddy has Flowtech full headers in a 70 340 Dart and the bottom of the #3/5 pipes hit the ground on every single bump. Those things are junk.