timing marks/balancer Top Dead Center

ok This is on a 94 vortec cpi .Im trying to figure this out. When my timing marks are lined right up on the timing chain sprockets the key hole on the crankshaft points to 0 on the timing tab like it is supposed to but there is no line on the balancer where zero is. There are 2 lines but neither one is even close to where 0 is. I know one is compression stroke and one is timing but it makes no sense neither one is on the crank at zero . Should i just mark a line for zero on the balancer and forget the other lines? i need to get this thing timed. Thanks

I assume that you replaced the timing chain and sprockets. Did the timing chain jump time or was it just sloppy? Did you move the either the crank or the cam shaft when the chain was off? In any case, if you install a new chain and sprockets, there are marks on each sprocket that line up as you said. But I am not 100% sure about the location of the Key slot on the crank shaft. The timing mark on the balancer for TDC of number 1 piston will actually line up at two different times during the 4 stroke cycle, once when number 1 piston is on the compression stroke and again on the exhaust stroke. Could your marks be 180° out? If you lined up the marks on the sprockets correctly and re-installed the balancer correctly, you should be close enough to start the truck assuming that you did not move the distributor.