[dwcsr]

For those who have PM'd me on making the rod for a different year master. When the rod is seated and the correct length, the master mounting flange will not be flush with the Booster unit flange when not bolted on. The master will sit against the rod, when not bolted in place, and leave a gap of approximately 0.065" which will close up when you tighten the nuts. This should take a lot of the guess work out of measuring the parts and trying to see if it’s the right length. Polish up the ends of the new rod so it doesn't gall the rod cups on each end.

You do need to have all the original parts, except the rod, so it seats properly into the unit and the retainer centers the front of the rod correctly. If you can't get the plastic disc off the rear of the old rod or it breaks. You need to tack weld a washer of the same dimensions in its place on the new rod. You still need the spring and retainer. The retainer when laid on a flat surface looks either like a spider or an upside down spider. It has all the legs bent in the same direction. To remove it from the unit gently grab a leg with some needle nose pliers on one side and hold it, Then push inward on the opposite side, then with a little twist pull the retainer out with the pliers. It installs by just pushing it into place in the bore groove with the bent legs pointing outward toward the master cylinder.

Pic below is of my boost unit with a used matching master of the same year and model. It shows the gap.

the gap.