May 12

Can I add extra wiring to OEM ballasts?

I have some OEM Denso and Hella ballasts. I'd like to add about 6-12" of wiring B/W BALLAST AND D2S PLUG. I believe both have internal igniters. I plan to use proper solder techniques with flux, special core solder, layers of heatShrink, techflex, etc...
Is this ok to do?
What's the max the wires can be extended?