LS V8 Engine Rebuild : COMP Cams Gear Drive System VS Single Chain VS Dual Chain here we have a factory GM single row chain and gear , this is a typical upgrade , this is by Comp Cams , which is also made by Cloyes , which is their double roller but even though this is twice as much chain as this one and it's a better quality metal in the gear , the chain will still stretch , especially when we've got spring pressures on some of these big high lift na engines that I build that exceed eight hundred pounds over the nose … to give us an insurance policy that the chain won't stretch , we won't have a failure in a part or have a problem with a tooth failing is why we chose to go with the Comp Cams gear drive setup , which is much more durable