Header Gaskets....

Ugh, I hate the weld bead "O-ring" header flanges. Its a poor way to do it as the flanges invariably bend when your torquing them down as there is nothing for them to bottom out onto. Have a machine shop throw them on the mill/belt sander and grind them flat. make sure you get the proper 273 sized port sized gaskets if your running the o-ring flanges, very important as the 340 O-rings wont even hit the bottom of the 273 ports. went through that with a set of 65 A Super comps on a 340.