PontiacBonnevilleClub.com

I saw an old post from 2010 about headlamp modification, as follows...

Second, putting a hi beam lamp in the low beam side...does this blind other drivers or cause any un-needed grief?

No, and no. You just have to trim off a plastic tab from the high-beam bulb connector, and narrow down the plastic tabs on the outer mounting ring. Dremel takes care of it in about a minute.

WARNING:
#1 State laws usually don't permit any such thing.
#2 Federal laws are more stringent than state laws and supersede them.
#3 It's dangerous

I cannot understand why someone would do this! It takes months, just to develop a lamp's optics by highly skilled optic engineers, designers to package it and then go to quality control, finally hitting production. Look, I've flown in a jet. It doesn't mean I'm going to fly it because someone tells me it's as easy as it looks. Would you want to put your 16 year old behind the wheel of this "experiment on wheels?"

A lot has changed in 9 years since the post you discovered. We have since discovered the 9011/9012 swap, coupled with relay harnesses. They tend to yield better, and don't suffer the same lifespan concerns encountered by moving the 9005 in to the 9006 slot.

And to your warnings:
1: They have to catch me first
2: Technically, any mounting of any bulb in any housing that it was not originally designed for brings the assembly out of DOT compliance. So, yes, using using a 9005 bulb in a 9006 housing is technically illegal.
3: Danger, is relative. 9005 is admittedly less safe, especially given that the end of the bulb is exposed and can produce more glare for oncoming drivers. 9012 bulbs aren't as bad, but typically do require a slight adjustment to keep the pattern courteous to other drivers.

And on the subject of #3, what is dangerous is me NOT having my headlights modified. I drive a county road at night with no street lighting. A 25 year old design cannot compete against modern headlight technologies. I can literally coming face to face with a new truck, with stock headlights, and I am 100% blinded because I sit below their beam cutoff. I literally couldn't see a thing if it walked in front of me. Is that safe?

These cars had no aftermarket following, so our options to upgrade key safety systems are rather limited. I don't believe any modifications should be made without giving due consideration to your gains, as well as the drawbacks, for yourself, and for those around you.

Thankfully the straight HID bulb swaps really aren't a thing around here. I have encountered one or two, it was not pretty.