Hi does the colour of the plug relate to shaft flex like teh shaft labels do, or was it just a design thing? I have a set of 1965 Dyna Powers on the way with the red plug, and I do have a set of 68=69 X31’s with black plug and are regular shafts.
To the best of my knowledge, the red plugs are the stiffer versions in most of the Dynapower releases. However, my 56 Dynas have black plugs are are X. I’m most certain that 66 and on are coded with red being stiffer.
Good to know, just got to waite for them to arrive now