Align the TDC mark on your harmonic balancer with the scale mounted on the front of the block and insert the dizzy in so the rotor is pointed at the #1 cylinder plug wire on the cap. If it wont run the, just align your marks and your dizzy, pull the dizzy, turn the engine over 360 degrees and reinstall the dizzy pointing at the #1 wire again. You can install the dizzy 180 degrees out. You can look in the valve cover oil fill hole and watch the valves to get it on the right stroke. But you have a 50/50 shot of getting it right without doing that.
Now this is from memory, If I have something wrong, speak up, but I think my method will get it running well enough to tune.
And a shameless plug [ sorry for the hijack, I am desperate] for my Ebay parts as my future depends on selling many of my treasured belongings to save my home, anybody need a 1978 Unimog, no rust, new paint and 50" tires. Well my w113 parts are listed under seller name "adogap66"