What is the proper number that should be on a 1970 455 Alternator?

 

You need to be a bit more specific. What car? Does it have A/C? If it's a 442 it's internally regualted. All others are externally regualted.

 

If so its a 1100890, hard to find! and expensive

 

It is a 442 with no a/c.

 

Tucson,

I'm waiting to hear the answer to this one too. I'm assuing a 70 W30 without AC would use the same alternator as a 442 with no AC.

regards,
bob

 

Tucson,

I did some digging on this site and came up with the following part numbers for 70 442 applications, both are internally regulated, which is why they are unique to 442s only:

1100880 - 37 amp - used w/o AC, rear defogger, or HD alternator
1100890 - 55 amp - used with AC, Rear Defog, or HD alternator

regards,
bob

 

Steven, what is the current $$$ range on a 1100890 alt.???

 

Mine is 1100662 with an internal regulator.

 

Do you have a camera?? If so, post pics of the front and back of your alternator.

 

I'll get photos tomorrow. Too cold tonight. Very cold for Tucson standards, down near 20 tonight and no higher than 37 in the day. Snowbirds are not liking this although I did see a few with shorts on today.

 

You know how that goes, I have heard of folks paying close to 2k for a rebuilt one for that final detail piece of the numbers matching resto, but really I have typically seen them from $400 - $1,200. Its a big range but typically the lower range is for ones with the wrong back or not stamped. The high end is for date matching all correct.

These were installed on 69 and 70 vettes as well so that ups the anti. I'm sure the numbers are different but the open face front end adds to the uniqueness.

 

Tucsonbob---check your pm's. Prices seem to be ALL OVER the place on these. As Stevengerard states, they can be pretty high but that's primarily from the Chevy demand.

Don't pay up much for the fact that one is rebuilt....that's not massive relative to the overall cost to have done as well as any detailing of the parts, etc.

Here's a 6 spoke open face alternator I recently did (When you read all this talk about "open face alternators" on here people are referring to the front case half and how the case is open all the way to the front edge between each spoke).

The second pic shows a "regular" Delco alternator....not an "open face" design.

 

wow, looks great Patton. And I agree you can get someone to rebuild it and make it a 63 amp, maybe even higher for around a 100 bucks, so if you can find one for the bottom range or even cheaper snag it. Like all these parts the minute you see one for 350, a month later one goes for 200 then you see one on evilpay go for 800.

Here's a pic of mine. Patton, any idea why mine has two grooves per fan blade and yours as three?

 

No telling on that. I just checked a few fan blades I have here and I see both styles. Note--on the one I pic'd it's not 3 ridges on every "blade". Don't know if those ridges were put in to stiffen the blades or for something else. Maybe they decided they needed additional stiffening on the wider blades??

So many oddball variations on these parts. I would say that your fan blade is correct for a '70 as it matches one I have here...2 ridges per blade all the way around. I don't state that as being "determinitive" or exclusive...I'm instead confirming that yours matches a known original I have.

Although....upon closer inspection yours appears to have the super rare "prominent trailing edge tab" on the widest blade!!!

 

Thanks Steven, it looks like I will have to take out a second loan on my house just to get one

I'll start keeping an eye out for one though

 

yep, glad I kept that and the master brake cylinder, though I did let my original radiator go - so I have been keeping an eye out for that and the ever elusive 66-70 cruise control stalk - that's the fun of this game always something to look for, fix or tweak.

 

Hi Guys,

Rocket......when you go to buy one of these open faced alternators make sure you check the BACK of the alternator. I've seen a number of these on Ebay that have an incorrect back half casting. The correct one has raised heat sinks over the regulator, not just slot holes in the casting. For the price people are asking for these alternators you should get an entirely correct one, not just a correct open faced front.

later,
bob

 

here is what mine looks like for reference

 

Thanks for the info Steven and Bob.

I'll save these photos for furture referance.

 

Another shot of the back....larger for more detail:

 

I was recently talking with Steven about these alternators. Here's pictures of the one I've stashed away until I'm ready to use it. The mounting hole on the back is closer to the 6:00 O'clock position than the one you guys have. For those of you who know much more about this than me, any ideas why this would be in a different location? John

P1010107-1.jpg

P1010110-1.jpg

P1010108-2.jpg

 

So, what do I have here?

 

Tucson,

I can't make out the 6th digit, but if it's a "9" as in "1100696" then it was stock on 66 Vettes with 327 and 427 engines rated at 350,390 and 425 hp when ordered with the K66 transistorized ignition. That's the good news. The less good news is it was also stock on Novas, Chevelles, and other Chevys that year.

Now.....you know how much we frown on people putting Vette parts on their 442s.....so please sell that alternator to some Vette nut for a ridiculous amount of $$$$ and get the right one for your car. Sheeeesh....the nerve of some people.

Have a great night,
bob

 

Must be one of the '69 versions...they had the slight differences in the finned back half. August 26, 1969 date code but that could have landed on a '70 car I would guess....who knows for sure?? The alternator I posted the pic of the back of above is also 1100890 55A and has a date code of "9L5"....so it's a bit later build....November 5, 1969.

I'll volunteer since nobody seems to want to take on this heavy responsibility......Why don't all of you with these open face alternators, finned-back alternators, etc send them to me and I'll sort this whole mess out for everyone.