I suppose you need lots of light out on Cape Cod to see any wild, renegade clams running across the road at night, right??
Those Hella puppies are also over 85 watts each, so you'll need a relay to power them. Do a search on here on "auxiliary lights" or "light relay" as we've covered driving light installation on here before. If you can't find it, then email me and I'll send a wiring diagram.
I've used Hella 500's and 550's (rectangular) on lots of different cars and they work great - you'll love 'em!
As an alternative, you could change those three-candle-power headlights you currently have to a pair of 65-85 watt H-4 style replacements, then you wouldn't have to install anything else. Bear in mind that you still might consider a relay to power even those, but I've seen some people get away without a headlight relay if they stay under 70 watts per bulb.
gn