benzdoctor,
i had the EXACT problem with my conversion on my 57.
could not get the drivers side banjo to stop leaking.
the calipers have been in and out of the repair process so many times, the crush washer mating surface on the caliper is fouled up, and not exactly flat.
with a suggestion for my buddy dave here from the bolt, i went to autozone and got soem thread sealer
http://www.permatex.com/products/Au...atex_High_Temperature_Thread_Sealant.htmcleaned the caliper and crush washers with brake cleaner, but a ver small amount of the sealer on the caliper area, and tighten the drap out of the bolt.
i let mine set over night, then procceded to bleed the brakes, and it has work great for the past 2 weeks, with about 200 miles on it and no leak at all.
if you have any problems with sucking air while cracking the bleeder on the caliper, mine was driving me crazy. i was using a hand held vacuum bleeder,a nd when i would just crack the bleeder and pump the vacuum pump, i would get nothing but air.
come to find out, the threads where the bleeder screw into were so LOOSE, when cracking the bleeder it would suck air around the bleeder threads, even using a speed bleeder.
so i wrapped a few turns of thread tape around it, and then i was able to get a good bleed without sucking air.
hope this helps you, because mine was driving me crazy, until i was told about this trick.
leonard