Hella makes a really great sealed beam conversion.
http://www.myhellalights.com/index.php/default/upgrade-kits-and-accessories/sealed-beam-conversion-headlamps/vision-plus-7in-conversion-headlamp/
http://www.buyheadlightbulbs.com/Hella-H6024-Sealed-Beam-Conversion-7-p/hel-002395031.htm