You should check out Metric Mechanic's website and read up on their piston sets and how they developed them. They have done quite a bit of testing with various forged pistons with different alloys of silicone in them. He has been able to make a durable, light, and close to stock expansion rate piston. He also uses hard anodizing on his pistons for a really hard surface along with lighter piston pins. I know Jim Rowe since the early 90's having personally visited his shop back then. I think he has the some of the most creative solutions for building performance and at the same time toughening up BMW motors and trannys. You might want to check out his rebuilt engines and go for the gusto. I ordered a 2200 sport engine from him 2 months ago. I spoke to Jim for quite a while before ordering it. I was going to rebuild it again myself but after our conversation and considering all the things he does in his rebuilds, I know in my heart that I don't have the time or the expertise to do the same job he would do and I don't feel like taking the engine out again after this. My engine began burning oil right from the get go as I put a set of Deves rings on a set of 9.3/1 KS pistons after I broke one of the stock rings putting one of the pistons in the bore. On top of that I don't think the gap was as tight as it should have been when I measured them down in the bore. I went with it anyway. They did not break in right and I think I also didn't help matter running a too rich mixture for the first thousand miles or so with a poorly setup Megasquirt system. I got all the bugs out and the engine now runs great but burns oil and has a lot of blow by. I have an Innovate AF gauge with Wide band O2 sensor on it now so that over-rich mixture won't happen again. Good luck and do some reading before you go with any forged pistons. They are definitely not all created equal. There are also a lot more choices out there then there were in the early days when guys went with Venolia pistons that clattered like hell until they warmed up and burned oil like crazy. OK if you were racing but not in a street car. Be really careful breaking in your freshly rebuilt engine whoever does it. Make sure your mechanical injection is working properly so the same doesn't happen to you.