Assuming those are 7" sealed beams (like I had), here's what I bought four years ago to convert them to LED:
Replace the Sealed Beam lamp with a "Hella H4" housing (I bought mine on Amazon - looks like they still sell them for ~$44 each - 7" is the same as 178mm)
Use a P43T bulb from LEDLight.com; you can select from either "White 6000K" or "Warm White 3000K" (when I bought mine, they only came in 6000K).
They're currently selling for about $20 each.
So for about $65 per headlight, you'd be converted over to LED.
Not only are the new lights noticeably brighter, I don't even notice the ammeter needle moving when I turn on the headlights now.