Adding Euro H4 headlights to a 85' US, questions...

When adding the H4's do I (really) need to upgrade or add a wiring harness? I am assuming all 928's came with the same wiring and switch?

I know on Rennlist years ago it was a popular mod to buy a relay for 911's to keep the headlight switch from failing, regardless of what lights you were running. I drank the cool aid, bought one and never installed it.
It's been in my desk drawer for years! Never had a failed switch either from too much load. My daytime job is not in foreign car electrics, FYI.

Would like to hear from anyone who is running H4's on their car.

The Euro lamps may require a different socket to fit the bulb. As I recall I added the socket for the Euro lamps and kept the socket for the US lamp so if I needed to go back to the US lamp it would be easy.

The Euro H4 headlamps require accurate set-up so you don't blind oncoming cars. Somewhere in my notes I have a diagram for the proper set-up if you need it.

My original three way matched it exactly. I think only the H5's require a plug "graft.' I do need to aim these things better. I have them close to where the old ones were hitting my back fence, but the light they throw is dramatically different. I don't know what kind of bulbs are in them because I bought these used, but they are seriously bright.