Tall deck 427 496 572 vortec 8100 guys, need help with headers

[NJM73]

Done quite a bit of searching thru here and have tried the few good suggestions I found without any luck. I have test fit without success sanderson bb8, and hooker 2463 headers. Currently have a butchered set of hedman 68610 chevelle headers that I want to replace.

Truck info, 4wd, currently has a tall deck 427, pushed 2" forward from where the factory 350 was, also had a hydraulic slave cylinder. I am getting ready to swap in a vortec 8100, the blocks are the same dimensions, including additional head height. Using the 427 for mock up so I can have the exhaust ready (o2sensors positioned amd welded in)

Looking for a set of headers that will fit better than what i have. I am going to try shaving an eighth inch off he frame rails soon to see if it will help at all (frame will get boxed while motor is out). I dont want to dent up either set i have yet until i can see if anyone has a similar setup (can still return both sanderson amd hooker)