Converting RD400 C-D-E chambers to fit 400F

[rearwheelslider]

I am looking into chamber options for my 79 400f. Do you know if it is possible to convert a set of chambers from an earlier model 400 to a 400f? I know the exhaust flange is flat on the F to accept the flat manifold of the 79, but other than that, are there any other things to consider regarding mounting and fitment? I have my eye on these beauties. I can fab something if the differences are slight. As far as I can tell, SpecII is the only mfr of 400f pipes and I cannot afford them. Thoughts?

[dgorms]

Pretty sure the rear mount is different.

[This Old Daytona]

I know my bike had "Non" Daytona pipes. They were fitted to my Daytona originally when I 1st owned her, as well as a set of FFPs.
 As far as I know..they fit with the exception of the rear mount...which were obviously modified in my bike.
 My same bike Daytona after decades is back w me now and the Moto Carrera Millennium pipes not their GP but the reg Millenniums  ( Doug) had a GREAT shop..I miss those days 
 But you mentioned different spigot fittings or fitting ?
 If so That's sumpthin I just learned.
  The 2 Stroke pipe builder Kenny Roberts ( Not that one! ). . What a coincidence though I always laugh   Welded up and adapted these pipes to my Daytona.
 She's locked up in my storage container but I might learn something from you guys here I can take pictures and send these to you or post them.
 

[SoCal250]

In addition to the already mentioned rear mounts...
The exhaust ports/studs are angled slightly on Daytona 2V0 cylinders compared to a 1A1 but I think you can make it work. The spacing of the stud is also slightly wider, 72 vs 68 mm.