Brett - It all depends on the condition of the alt when I get it in my hands. I don't quote firm prices on these since the condition varies so much. There are "easy" alts that come apart easily, no fasteners are stuck, no stripped threads, no snapped off screws, etc.....and then there are the "problem childs" with stuck case halves, corroded/broken case screws, stripped threads, cracks in the case, etc (very common on some Olds alternators). One I restored awhile back had about 15 different cracks in the case halves and a current project had the front case half broken in two. Then there's everything in between. I'll look at some I did and see if I can come up with a "base case" range and get back to you.
Nice...mine works fine and looks OK but it does not look no where near as good as the one you posted,
I've had stamps made when I have found an original stamp to copy or I am provided whatever two letter codes are needed. I haven't done the single letter stamp yet but it is "do-able". I've made a couple stamps for Olds alts since I do a lot of those and know the codes used (Assembly Manual info as you know). I have a "BD" stamp for a couple Buick alts I did in the recent past for some folks on this site. I like the "natural"/bare look on the cases. Clearcoating can change the "look" but may offer some protection. The fan and pulley (but not the alum case) on the Olds alt shown above are clearcoated.....I want to see what effect, if any, it has on preserving the zinc plated parts over time and it's going on a local car so I'll be able to monitor it. Wiping the case down periodically (if left bare) with something like Boeshield should help preserve the finish. Over time, the aluminum will change colors to a "greyish" color when left bare. Obviously, storage conditions and environment have an effect on the aging of the bare cases. That's where something like a Boeshield or possibly a Gibbs Oil type product could be employed.
Steve - You'll have to fight the owner of that one to get it. Not worth it since it's for a '70 Olds and it's internally regulated, unlike our Buicks. It's a somewhat rare open face alternator - I say "somewhat" because it has a new casting open face front half but does have a rare original back half that has a unique look with some raised cooling fins on the back face of the case where the internal regulator was mounted inside. Ultimately, Olds stopped using these and went back to the traditional "closed face" style and the external voltage regulators. Some Buicks and Pontiacs in the '70/71 era also used another version of the open face but they used 5 spoke front halves (instead of the 6 spoke used on 69/70 Olds) and they did not use the cooling-fin-back halves. I don't remember if the Buick and Pontiac alts were internally or externally regulated. EDIT AND ADD: Oh yeah Dave - on Olds's, at least with factory AC, the ink stamps aren't always a big deal to the owner/customer...unfortunately, when mounted on the bracket, the part of the case where the factory put those stamps is facing DOWN! Uggh.
What i actually meant was "inline" for your work, though I did notice that the alternator was A) beautifully done and B) a little unusual. Tell Brett to wait his darn turn!
Here's a pic of the "raised fin" (sometimes called "diamond back" due to the overall orientation/look of the fin set) style back half. This is a NOS alt for a '70 Chevy but it's the same back as the Olds used in '70. '69s are pretty much the same but the bolt boss (at around 4:00) is more flush on a '69 back half. Therein lies "the catch" on the back halves......you have to compete with Chevy folks for them.
Fwiw, Pontiac was consistent in using the 6 spoke front half and diamond back rears on the 69 TAs and 70 birds. The 5 spoke open face was used in 71 with the more common rear half. These are internally regulated.
Patton. For some reason that looks different in the back than my friends 442's? No I am going to have to check. His are originals.
Dave - The back I show is a correct back for a '70 442. The '69's used essentially the same thing but with the more "flush" bolt boss. I have about 6 other original '69 and '70 Olds 442/etc alts here if you guys need more proof.
Patton, my mind is polluted with Buick alternators. Maybe that is why? I have been working on my friends several 72 442s. I need to look at those.
What is the trick to getting the aluminum so clean? I wash them and sometimes do a light media blast but often have dark spots in the aluminum that remain, probably from corrosion.
Dave - DON'T look at your friend's 72 442....nor a '71 for that matter. Those years DID NOT USE the same-style-as-69/70 alternators. '71 did not use a 6 spoke open face (I'm not sure what they used...maybe 5 spoke open face, maybe not) and did not use the finned "diamondback" back half. In '72, they went back to the firewall-mounted external regulator and back to the "traditional" looking alt cases. '69 and '70 were internally regulated and used the open face/diamondback cases.