I used an ebay head gasket on mine 3 or 4 years ago,has held up fine,and I ride it like I stole it.Cant remember manufacturer name,but I think it was South American.Would probably recognize maker if I saw the name,or I can go to my storage and look,still have package with leftover gaskets.But I used to build Mercedes /BMW engines for a living,(mostly headgaskets lol)and Had to be practically OCD about assembly and torque values because they will gladly bite you in the butt otherwise.I had used that companies gaskets back then with good results,recognized name,which(besides availability) was only reason I rolled dice on non-OEM gasket set.I do remember that during the re-torque process after 1st warmup,the nuts surprised me how much movement it took to put them in spec.I got the feeling that the re-torque was nowhere to get lazy,and tore down & checked again after 100 miles or so,and they still tightened a bit more.