Alt Mount - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Bullzak_83 · 09-21-2021, 09:53 PM

Question, does anyone have a picture of how this bracket for the alt,mounts.
I know this is not right, but I'm trying to figure out the correct way of setting it up. It's on my 70 cst 10. I have cut a extension to bring it out away from the block. I have evan noticed that the fan on the alternator was dragging the bracket somewhat, I actually ground the bracket, so it would clear the fan.

**Warrens69GMC** · 09-21-2021, 10:12 PM

Here is a 307, same water pump as 350, short water pump same brackets
http://67-72chevytrucks.com/vboard/s...89&postcount=8

zosoppp · 09-21-2021, 10:24 PM

on my 1970 c10, sbc350, I have the upper arm connected to the REAR of the alternator's top ear with the bolt going in from the firewall side. Also the engine end of the upper arm is connected to the head with the same bolt as the base, no spacer forward.

**LockDoc** · 09-21-2021, 10:31 PM

Quote:

Originally Posted by Bullzak_83

Question, does anyone have a picture of how this bracket for the alt,mounts.
I know this is not right, but I'm trying to figure out the correct way of setting it up. It's on my 70 cst 10. I have cut a extension to bring it out away from the block. I have evan noticed that the fan on the alternator was dragging the bracket somewhat, I actually ground the bracket, so it would clear the fan.

You have the wrong adjustment arm. If you notice the one on zosoppp's engine has a lot more curve to it. That is the one you need so it can be mounted on the back of the boss that the bolt goes into.... I think it also has an offset where it bolts to the lower bracket.

LockDoc

Bullzak_83 · 09-21-2021, 10:31 PM

Quote:

Originally Posted by zosoppp

on my 1970 c10, sbc350, I have the upper arm connected to the REAR of the alternator's top ear with the bolt going in from the firewall side. Also the engine end of the upper arm is connected to the head with the same bolt as the base, no spacer forward.

I've to attach on the back side, but the width of the bracket would not allow the bolt hole to line up with the bracket, i guess I could modify the bracket

Bullzak_83 · 09-21-2021, 10:33 PM

Quote:

Originally Posted by Warrens69GMC

Here is a 307, same water pump as 350, short water pump same brackets
http://67-72chevytrucks.com/vboard/s...89&postcount=8

Could you resend the link, i couldn't get to open.

**Warrens69GMC** · 09-21-2021, 10:36 PM

here
https://67-72chevytrucks.com/vboard/...89&postcount=8

zosoppp · 09-21-2021, 10:39 PM

Quote:

Originally Posted by LockDoc

You have the wrong adjustment arm. If you notice the one on zosoppp's engine has a lot more curve to it. That is the one you need so it can be mounted on the back of the boss that the bolt goes into.... I think it also has an offset where it bolts to the lower bracket.

LockDoc

Here is the lower end of the upper bracket.

**LockDoc** · 09-21-2021, 10:41 PM

Quote:

Originally Posted by zosoppp

Here is the lower end of the upper bracket.

OK, I see that that one is straight. Thanks.

LockDoc

zosoppp · 09-21-2021, 10:43 PM

Quote:

Originally Posted by LockDoc

OK, I see that that one is straight. Thanks.

LockDoc

Actually I was thinking that there might be a little bend in it from that photo, hard to tell, though.

**LockDoc** · 09-21-2021, 10:47 PM

Quote:

Originally Posted by zosoppp

Actually I was thinking that there might be a little bend in it from that photo, hard to tell, though.

Could be. A picture of the whole arm from more straight on would be the only way to tell for sure.

LockDoc

zosoppp · 09-21-2021, 11:13 PM

Quote:

Originally Posted by LockDoc

Could be. A picture of the whole arm from more straight on would be the only way to tell for sure.

LockDoc

Found another angle installed, definitely looks like two bends in it.

**LockDoc** · 09-21-2021, 11:53 PM

Quote:

Originally Posted by zosoppp

Found another angle installed, definitely looks like two bends in it.

Yep, I thought it should have offset bends in it.

LockDoc

NorCalC20LWB · 09-22-2021, 03:58 PM

I had the same issue, bought the longer year alt bracket which arrived straight, no bend at all. Put a couple bends in it with a vice, very easy and worked great.

**Grumpy old man** · 09-23-2021, 08:40 AM

With the short water pump the 71-72 brackets work note the lower bracket in the picture below . The generic aftermarket brackets sold don't work well with taller valve covers .

zosoppp · 09-23-2021, 09:58 AM

Yeah, that's one of the gotchas of going to the internally regulated 10SI is that the alternator does not have the clearance for the valve cover when changing/adjusting the belt tension.

I assume that the 12si is similar in that regard.

Next time I have to do that I might just pull the valve cover to get the belt off and on again.

Bullzak_83 · 09-30-2021, 05:51 PM

Hey Grumpy Old Man, that's the problem I having. I have tall valve covers and that's why I added the extension. You don't happen to have a part number for that longer bracket on the top do you?

09-21-2021, 09:53 PM	#1
Bullzak_83 Registered User Join Date: Oct 2020 Location: Arlington,TX Posts: 87	Alt Mount Question, does anyone have a picture of how this bracket for the alt,mounts. I know this is not right, but I'm trying to figure out the correct way of setting it up. It's on my 70 cst 10. I have cut a extension to bring it out away from the block. I have evan noticed that the fan on the alternator was dragging the bracket somewhat, I actually ground the bracket, so it would clear the fan. Attached Images

09-21-2021, 10:12 PM	#2
Warrens69GMC Registered User Join Date: Jan 2003 Location: Safford,AZ Posts: 3,626	Re: Alt Mount Here is a 307, same water pump as 350, short water pump same brackets http://67-72chevytrucks.com/vboard/s...89&postcount=8 __________________ 1969 307, t350 1950 Chevy Wagon 1978 Big 10 1967 C10, 250,3-OTT

09-21-2021, 10:24 PM	#3
zosoppp Registered User Join Date: Mar 2014 Location: Lincoln Park, NJ Posts: 193	Re: Alt Mount on my 1970 c10, sbc350, I have the upper arm connected to the REAR of the alternator's top ear with the bolt going in from the firewall side. Also the engine end of the upper arm is connected to the head with the same bolt as the base, no spacer forward. Attached Images __________________ 1970 C10 LWB 350SBC, SM330 Muncie (not saginaw SM326) (on tree), 3.07 open (assumed), PS, PB, Idiot lights

09-21-2021, 10:36 PM	#7
Warrens69GMC Registered User Join Date: Jan 2003 Location: Safford,AZ Posts: 3,626	Re: Alt Mount here https://67-72chevytrucks.com/vboard/...89&postcount=8 __________________ 1969 307, t350 1950 Chevy Wagon 1978 Big 10 1967 C10, 250,3-OTT

09-22-2021, 03:58 PM	#14
NorCalC20LWB Registered User Join Date: Mar 2015 Location: Bigfork, MT Posts: 466	Re: Alt Mount I had the same issue, bought the longer year alt bracket which arrived straight, no bend at all. Put a couple bends in it with a vice, very easy and worked great. Attached Images

09-23-2021, 08:40 AM	#15
Grumpy old man Senior Member Join Date: Dec 2013 Location: Gods country East,Tn Posts: 8,545	Re: Alt Mount With the short water pump the 71-72 brackets work note the lower bracket in the picture below . The generic aftermarket brackets sold don't work well with taller valve covers . Attached Images __________________ 1967 Factory short bed - Old school '71 - 350 / 4bolt / 487 heads / Edelbrock C3BX Muncie M-22 4 speed / Hurst Comp plus Factory 12 bolt posi 3.73 / 255-70-15 Smoothed firewall / Factory cowl induction Power disc brakes / power steering / 3.5-5" drop

09-23-2021, 09:58 AM	#16
zosoppp Registered User Join Date: Mar 2014 Location: Lincoln Park, NJ Posts: 193	Re: Alt Mount Yeah, that's one of the gotchas of going to the internally regulated 10SI is that the alternator does not have the clearance for the valve cover when changing/adjusting the belt tension. I assume that the 12si is similar in that regard. Next time I have to do that I might just pull the valve cover to get the belt off and on again. __________________ 1970 C10 LWB 350SBC, SM330 Muncie (not saginaw SM326) (on tree), 3.07 open (assumed), PS, PB, Idiot lights

09-30-2021, 05:51 PM	#17
Bullzak_83 Registered User Join Date: Oct 2020 Location: Arlington,TX Posts: 87	Re: Alt Mount Hey Grumpy Old Man, that's the problem I having. I have tall valve covers and that's why I added the extension. You don't happen to have a part number for that longer bracket on the top do you?



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.