I think I catch your drift, Schurkey. I have a Mr. Gasket variable vac advance kit. It includes a new center plate, a set of weights, an asst of springs, and plastic weight bushings to slide over the pins. In your photo #20 you show worn pins. So I guess you're suggesting that I first inspect the condition of the pins and the possbility that my mechanism could be worn, sloppy, not moving freely, etc.
Yup--but--that sounds like a CENTRIFUGAL advance kit, not a vacuum advance kit.
*How does one change the pins if I am able to find them at my local parts store? It would probably pay for me to do so before I press the plastic bushings into the new weights and go to drop the weights on the pins, right?
Change the pins by knocking them out with a hammer from the top. Be sure to support the plate they ride in. Depending on the plastic bushings used, you may not need to change the pins; the plastic will ride on enough of the non-worn surface to work OK. Not all styles of pins are available.
*Do I need to remove the dist. itself at any point? Do I need to inspect the gear itself and must I remove the dist to do so? ( I think I read about lifting or rocking the dist body somehow to check for play (?)
"I" would pull the distributor. But then I have lots of experience putting it back in, and it's no big deal. I'm not sure I'd recommend that course of action for you, though. It's unlikely that the distributor gear is bad. The defining points are whether or not 1) the centrifugal advance moves freely once you remove the springs and weights; and 2) the pickup coil rotates freely on the pivot post when you disconnect the vacuum advance. If they do--leave the distributor in place. If either the centrifugal advance or the pickup coil binds--at all--it has to come apart to be inspected, cleaned and lubed.
*In some of the photos I see evidence of lube. What areas should be lubed and is there a specific product I should use?
I put a THIN film of lube on the shaft in the area shown in photo 20; and a THIN film along the main shaft where it goes through the housing. Similarly, a THIN film on the pivot pins and where the weights slide on the nylon pads (newer distributors don't have nylon pads, it's just stamped metal)
There is a grease reservoir sealed with a plastic "cap" under the pickup coil; but you generally destroy the plastic cap if you pull it off; and far as I know you can only buy new ones in a pack of five or something. (Delco P/N 1837617) Put a THIN film of grease on the pivot post for the pickup coil, too.
I use Lubriplate 105 motor assembly grease. Available at any NAPA, probably available at any other parts store, too. But then, most any white grease would work ok.
*Do you have any recommendation as to which spring would be the best starting point once I begin experimenting with the variable advance unit?
No, not really. And the weights supplied in the recurve kit can go straight into the recycle bin. Much too light. Try re-using the stock weights.
If you were starting fresh, the Crane adjustable vacuum advance kit comes with an assortment of centrifugal advance springs; and you don't pay for weights that you don't need.
Another possibility is to just buy a new distributor shaft kit from GM. New shaft, new pivot pins, new weights, new center plate, you even get a new rotor. Everything is nice 'n' virginal. AND it's the same stuff used in the distributor that goes in the semi-hot crate engines like the ZZ4 and HO 454. It may not need further tuning--the advance is pretty good as-is. List price is frightfully high, but if you can arrange for a discount it becomes entirely reasonable. I think I paid ~$65 about a year ago. GM part number 01894379 (if that doesn't work, try it without the first 0--just 1894379.)
btw...What an awesome document you compiled...I haven't even walked out to the car and I already feel more confident having read through it once!