Heddon 8 1 3/4 HDH or E silk line

Question
I just bought a minty Heddon #14 Thorobred 8' 3 piece 1 3/4 ferrule. I want to go silk and fish this rod. Does the HDH or E make this a DT5.5 silk or DT6..There are some silk lines avalible in half sizes. I have fished #6 model20 8 1'2" before and it called for a straight #6, with 2ferrule...Should I go with a #6 silk or 5.5

Thanks
-Neil

Answer
Neil,
Lines aren't very meaningful to me . I have fished silk but prefer modern lines. But I am a 'rod' guy .
Have you seen this ?
AFTMA #   DT   WF            LEVEL   MM - OD   IN - OD
1   --   --       I   0.56   .022
2   --   --       H   0.63   .025
3   IFI   IFG       G   0.76   .030
4   HFH   HFG       F   0.89   .035
5   HEH   HEG       E   1.02   .040
6   HDH   HDG       D   1.14   .045
7   HCH   HCF       C   1.27   .050
8   GBG   GBF       B   1.40   .055
9   GAG   GAF       A   1.52   .060
10   G2AG   G2AF       2A   1.65   .066
11   G3AG   G3AF       3A   1.78   .070
12   G4AG   G4AF       4A   1.91   .073

I am doubting most casters could not feel a difference between silk , DT5.5 and DT6.

I think the answer is; depends on how far you want to cast and if you are throwing light or heavy flies. If you are a dry fly size 20 kind of fisherman, go with 5.5

Luck ,
Mac