Got a bit of confusion I'm hoping someone here can help me out with. Came into possession of a 1978 silver anniversary edition (L-48 in mostly stock configuration) a few months ago. Have started fixing or replacing various bits and pieces (probably a long process...). One thing I want to do is fix the alternator adjusting bracket/brace. As illustrated in the photo I've supplied, it seems to be two parts of two braces, perhaps JB Welded together.



While i don't seem to have any serious alternator issues at the moment...it looks rather "Bubba-ish" and I'd like to put the right bracket in. While checking the various parts houses...there seems to be two different upper brackets available:: a longer one for the "original?" alternator...and a shorter one with a less pronounced angle for a 70 amp alt. The broken part of the bracket which is attached to the engine block seems to resemble the longer one.

Another thing I'm not sure of is if I have a 70-amp alternator in there. I tried looking at the numbers, but as you can see in the next pic, it looks like someone has been whacking on them with a screwdriver or something;



It certainly looks like it says "70" on the right of the top line. So at this point I'm ready to assume it's a delco-remy 70-amp alternator. Can somebody with a non-hammered-on 70 amp confirm for me?

Thanks.

 

amps do not affect physical size.
only thing i can guess is someone didn't trust the bracket or it cracked so they double it up.
i never heard about a shorter swing for amps?

i just put an 85 amp alt that matches the stock
67amp in size

 

Here's what I'm talking about:

I snipped this off of Davies site:

That's what has me confused. I could swap in a different alternator...but as I said, I don't seem to have any problems with the current one. I just need to figure which brace to use.

 

take off the one you have, take it to the store.
i am surprised there are 2, i'm thinking must be
for something besides amps.
all the ones i have seen are long.
my 68 would throw a belt at high rpms.
A/C car, power steering
shrug

 

The Davis ad is incorrect. In 1978 there were 3 alternators, 61 amp, 42 amp, and 63 amp.

In 79 they added the 70amp.which took the gm #14015511 alternator bracket.

GM #460754 can be used for 78 and 79 with the 3 other alternators.

 

interesting, if there is only 1 belt for the car
then I guess the alt pulley must be a different
size?
great another special part

 

You certainly have a 70 AMP and from the numbers 1101041 is from a 79.
A different lower bracket could have been installed over the years by a previous owner?
Usually installed on later years was a Aluminum lower bracket.
If your lower bracket is made from Aluminum then the upper Brace would GM #14015511 from the Davies photo.
If the lower bracket is made of Iron then the upper Brace would be GM #460754 from the Davies photo.
Even (IF) the 70 AMP alternator is not correct for a 78 it is still a 10SI frame and is fine to use.
You just need to determine what lower bracket you have and match to the correct upper Brace.

 

Here is what Davies may be using as reference for there numbers?

 

Well, I guess tomorrow I'll poke my face down below and see if I can figure out what the lower is. As I said, the current upper seems to be longer with more of the "hockey stick" shape to it...only with a portion of another brace welded onto it, (being as the longer one seems to be missing about 2 inches of the bottom part of the slot the positioning bolt goes into.) My best guess at this point is that the PO kept the original brace...and just stuck a 70-amp alternator on it. I checked a couple of other parts sites and what I have on there now certainly looks very like the "non-70-amp" 460754 brace.

Thanks for the suggestions

 

The 460754 Brace would be my guess what you need.
Here is the Lower Bracket part numbers...

 

If your ordering a Brace you may want to also include the Belt Guard that attaches to the Brace.
LINK:https://corvetteparts.com/item/guide-fan-belt-1977-1981

 

To my knowledge, NO GM car built after 1955 had just ONE accessory belt on it. (disregarding modern single drive-belt systems) There were always two belts (minimum). If the vehicle only had an alternator to turn, there would be the belt on the alternator, which would also go around the crank pulley and the water pump pulley AND there would also be a small belt running on just the water pump and crank pulleys. The latter (second) pulley was primarily there to act as a fail-safe backup, if the other belt failed. You would still be able to drive home or get to a nearby repair facility. That second belt also shared the water pump load with the other belt, making BOTH more reliable.

 

All great advise. Lastly, I would add a flat washer to the bolt. In your picture it looks like the head of the bolt partially slipped off the bracket. Jerry

 

If you get tired of the squealing belts you can switch to a March Serpentine Belt Conversion like I did and really open up your engine compartment. The parts work great from March Performance but their early Powder Coating was junk and peeled off in sheets.