There are 2 easy solutions for that . Start with a 12 volt lamp , which will take a lot higher voltage than 14.4 or go with the capacitor setup.
The 12 volt LED lamps are cheaper too.
I have now done 3 of these conversions with no issues at all.
It sure beats trying to replace sealed beam headlights at $25-$50 a pop.
I may try to mount the rectifier near the stator so the tail light will be LED also .
If i change it , i will post more pictures.