Ron - I have one of the very early sets of 4-pipe headers that FFR made. To say the flanges and port welds are ugly...well, that would possibly be the understatement of the year!
I had a terrible time with header leaks until I tried the Earl's. I ran them for about 22,000 miles until I swapped engines...never a single leak. At the time of the engine swap, I ordered new set of graphite seals for them ($19), and they're still going strong with another 20,000+ miles on this engine...still never a leak.
I also have not had any problems with loose header bolts like I have with other gaskets.
http://www.holley.com/HiOctn/ProdLin.../HeadSeal.html