Chances are the V and the dot are meant to line up. If that is not the case you are missing some parts or have the wrong timing cover? If you try to change the timing by moving the distributor the computer will try to compensate the opposite way.
Try this, warm the engine up, find a good vac. source in the intake, plug all vac. hoses you remove, hook a vac. gauge to this source. Fire up the engine again and using the idle screw or however your application sets idle, idle the engine till it almost stalls. OH, should have loosened the distributor already if it is very tight, remove and plug vac. advance lines, advance the dist. till you see gauge reading start to fall off, 15 to 20 in. lbs will be the rang you are looking for, and back it up to your highest reading and remove about 1 inch of vac. from there. Replace everything like you found it. If engine pings under power repeat and remove .5 inch at a time. NOTE engine cant be hunting all over the place, needs the smoothest, lowest idle you can get. Also if you can't get a steady vac. reading while turning the dist., that is the computer doing what it is designed to do, put the dot in the notch and rock out. Another note, I have never done this on a computer controlled engine but it is the best way to set base timing on a carbed. engine, I put this out there because if the vacuum gauge gives you a steady reading it will work I also am betting you will get the best reading close to where the dot and notch line up, GM probably didn't intend for you to monkey with it very much. RTR
