340 X heads and Doug's D453 headers

Hi BooGTS
After reading through many of the header postings Im planning on going with long tube headers for sure on a '69 340 x head in my 68 Notch 4spd. Shorties don't seem to have a guaranteed fit advantage . I have p/s , manual brakes. Front is lowered 2" via drop spindle. Im moving towards installing the 340 to begin a Shaker Hood fab fest and should start some header test fitting as well I suppose. How did your Dougs work out for you assuming you got your 340 swap done? Obviously im curious about ground clearance, fit and performance.
Thanks
Tim