Timing mark

The lower chain has a silver link that is aligned with the mark on the sprocket with the engine locked at top dead center. The upper chain is aligned to a mark on the lower drive sprocket using the gold colored link. There are two silver links, one is 22 rollers away from the gold link, the other is 16 rollers away. The 22 roller side goes to the intake cam. With both cams in position the marks line up with the silver links on the chain. However if the chain came off with the engine running there is likely valve damage from them hitting the pistons, unless you have already repaired that. The images below are from the GA series manual and should cover that engine.