timing advance (to much)
Braze/weld the inside of the slots. I rarely, almost never, do the outer sides anymore.
Get a Mr Gasket spring kit and put some lighter springs on it. The Chevy kit works fine.
A neat way to get the advance you put in it. Protractor or a degree wheel, grab a zip tie as pointer and tape it to the shaft tower, turn tower and note degrees. The chart above is really good.
You can also take a piece of cardbord, cut a hole in the center, slide it down over the shat, put rotor on with zip tie taped to it and mark sweep beginning and end points. Measure with a protractor or angle finder.