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2025 C3 ('68-'73) of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
Replacing Alternator
My alternator was over charging my battery to over heat and smell like toxic waist… A friend of mine had an extra alternator, looks exactly the same as my old one and plugged right in. It’s working great…😊
New I have to buy one to replace the one I borrowed. Looking on various corvette parts pages I see 70, 85 and 100 amp alternators… Does it make a difference which I buy. My 71 350 is pretty much stock except for an upgraded stereo radio but no extra amps or anything. I do have AC, no power windows either. How much horsepower will it add if I get the chrome one…🤣🤣🤣
Well, for certain the chrome plated case will add at least 50 H.P. to your engine and make the alternator last years longer.
O.K.
Now for a serious answer. My 77 with Air came factory with a 63amp. alternator.
If you are just looking at a replacement alternator and have no want or need to upgrade the wiring. The 70 amp would be the biggest you would look at. Or perhaps look a little harder for a correct replacement which I believe would be a 61 or 63 amp alternator.
As per the answer that got in before mine, we must have been typing at the same time.
An 80 or 100 amp alternator is great with electric fans and other accessories. BUT, definitely requires upgrading the wiring to handle the additional load.
I would rebuild your old one if original ..
do not toss.. the chinesium rebuilds smell and draw more hp..
pic of old alternator? May have date and amps on it
I wouldn’t go over 63 amps if replacing unless wiring upgraded.
not sure what yours came with originally..42, 61, 63 amp? Probably higher with ac
Believe it or not the 10si alternators amp ranges between 37-63 all used the same general rebuild parts...
Part numbers and leg work done,,,your welcome...
All U.S.A. made parts except the 40ohm resistor
My total cost for these parts $42.00
Last edited by bmotojoe; Jan 7, 2023 at 11:28 AM.
Reason: Updated 1 Superseded Part Number
What is the wiring upgrade that needs to be done? I am actually wanting to upgrade my 63a to a 100 or maybe even 140 due to adding dual electric fans, Vintage air and a modest stereo system but don’t want to burn it down!
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
Originally Posted by interpon
I would rebuild your old one if original ..
do not toss.. the chinesium rebuilds smell and draw more hp..
pic of old alternator? May have date and amps on it
I wouldn’t go over 63 amps if replacing unless wiring upgraded.
not sure what yours came with originally..42, 61, 63 amp? Probably higher with ac
My old alternator is stamped
1102480 61A
6C24 12V NEG
Dont think it’s the original, it does have
Delco - Remy embossed on the back of th casing…
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
Originally Posted by bmotojoe
May I ask where is the through bolt and insulator?
Yes, when I was trying to losen the nut off the through bolt it wouldn’t come off, it was frozen on. I sprayed it with WD 40 but still couldn’t get it off. Then the whole bolt started turning and I noticed the red plastic insulator was cracked. Anyway the whole bolt came out and the insulator was in two pieces… Can that be fixed, Not sure if I still have the bolt.
Yes, when I was trying to losen the nut off the through bolt it wouldn’t come off, it was frozen on. I sprayed it with WD 40 but still couldn’t get it off. Then the whole bolt started turning and I noticed the red plastic insulator was cracked. Anyway the whole bolt came out and the insulator was in two pieces… Can that be fixed, Not sure if I still have the bolt.
If you open that alternator and there is a single loose flanged nut with no home it came from that missing through bolt, that's why you see 2 nuts in the NOS bolt kit I posted. 1 for the battery wire and one securing through bolt to rectifier.
If your alternator was over charging, sounds like the voltage regulator. All these rebuilt kits come with a regulator. Easy to replace. The only real special tool you will need is a toothpick. (To hold the brushes back).
Replacing Alternator
