Aftermarket H4 bulbs for low beams

I bought some "diamond" Xenon aftermarket H4 low beam bulbs for the 88 Testarossa. They say they are OEM replacements for 85-89 Testarossa, and have a 55 w draw according to their materials. It would seem that this would be a straight plug in replacement without the need for a relay, but I don't want to cause electrical problems for my TR, which already runs a Macintosh Amp direct from the battery on its own fuses (installed by/for former owner). Any thoughts on whether I can just put in the new bulbs/lamps without any additional wiring work?