I'm one of the few that don't like the gear drive. I bought one several years ago and installed it on our Suburban. IMO, its poorly made. The installation is very fiddly, requiring grinding off the idler shafts for the proper fit, which is not very well defined. The cam gear did not fit, I'm told you are supposed to beat it on, but that is not something I prefer to do with my cams. Seems a good way to knock the cam button out of the back of the block. After I got it installed, it sounded like a rock crusher. I didn't really notice any performance difference to the chain. I ran it for about 500 miles and then went back to a chain. On my current AMG engine, I went with a chain as well. I know some seem to like the gear drives, but I favor the chain. FWIW, Bill Heath recommends a timing chain as well.