HID full size ballast install?

[Kaotic Lazagna]

It's not necessarily the cutoff that's the problem. It's that the reflector bowls were designed for halogen bulbs, not HID bulbs, which emit light a different way. You may not see it, but glare may be coming from the headlights if seen head on. You'll know if you have that problem as people will either high beam you, or flip you off. I think people have made blockers that go on the bottom of the bulb to help limit the glare problem.