1969 or 1972 BBC alternator bracket differences - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Accelo · 04-28-2022, 12:27 PM

I am interested in the differences BBC alternator brackets.
I have what I believe is a 67-70 bracket (with the wood floor).

A recent 1971-72 BBC bracket just sold looks different. The gray background picture.

What changed on the motor and why are they different it my question.
Cheers.

**uncle** · 04-28-2022, 02:26 PM

Google big block alternator brackets from this site and you’ll see the differences. I tried but for some reason it won’t let me download the picture.

mr.mud1 · 04-29-2022, 12:57 AM

i don't know why the bracket changed but here's the alternator bracket on my big block 72?

Accelo · 04-29-2022, 01:05 AM

Beautiful job on the motor/frame. Thanks for the picture. Do you have a picture of the support rod on the back of the bracket? Also interested in the length of the rod.

If others could post a close up of this area of the earlier brackets maybe I could figure out what changed. If it's the intake or what exactly.

mr.mud1 · 04-29-2022, 01:32 AM

thanks,my truck is coming together,i'll get you a picture of that rear rod and some measurements tomorrow when i go out to the shop,here's a picture of the rod behind the alternator hanging up after paint.the main bracket bolts to the front of the head,not the intake and the rod,to the head as well.take care.Greg

mr.mud1 · 04-29-2022, 08:23 AM

here's a couple pictures of the rear brace on the alternator of my 72 big block truck.it's hard to hold the tape and take a picture but it's about 11 inches long over all.hope that's a help.take care.Greg

**uncle** · 04-29-2022, 11:18 AM

68/69 bolted to front of intake. 70/71 bolted on top of intake. 68/69 also had high rise cast intake.

Accelo · 04-29-2022, 12:08 PM

Ok, it's becoming clearer what the differences are.
Both the 68-69 and the 70-71 brackets bolted to the intake.
The boss on the 68-69 intake was eliminated in 1970.
So the 1970-71 bracket has the tab welded on. The attaches to one of the forward intake hold down bolts.
In 1972 GM quit using any attachment bolts located on the intake and just bolted the bracket to the front of the head. The necessitated the addition of a support rod.

KQQL IT · 04-29-2022, 10:04 PM

Our 68

04-28-2022, 12:27 PM	#1
Accelo Registered User Join Date: Mar 2015 Location: washington Posts: 2,178	1969 or 1972 BBC alternator bracket differences I am interested in the differences BBC alternator brackets. I have what I believe is a 67-70 bracket (with the wood floor). A recent 1971-72 BBC bracket just sold looks different. The gray background picture. What changed on the motor and why are they different it my question. Cheers. Attached Images Last edited by Accelo; 04-28-2022 at 12:34 PM.

04-28-2022, 02:26 PM	#2
uncle Senior Member Join Date: Aug 2003 Location: Conyers,Ga. Posts: 7,285	Re: 1969 or 1972 BBC alternator bracket differences Google big block alternator brackets from this site and you’ll see the differences. I tried but for some reason it won’t let me download the picture.

04-29-2022, 12:57 AM	#3
mr.mud1 Registered User Join Date: Dec 2020 Location: Joggins Nova Scotia Posts: 1,599	Re: 1969 or 1972 BBC alternator bracket differences i don't know why the bracket changed but here's the alternator bracket on my big block 72? Attached Images

04-29-2022, 01:05 AM	#4
Accelo Registered User Join Date: Mar 2015 Location: washington Posts: 2,178	Re: 1969 or 1972 BBC alternator bracket differences Beautiful job on the motor/frame. Thanks for the picture. Do you have a picture of the support rod on the back of the bracket? Also interested in the length of the rod. If others could post a close up of this area of the earlier brackets maybe I could figure out what changed. If it's the intake or what exactly. Attached Images

04-29-2022, 01:32 AM	#5
mr.mud1 Registered User Join Date: Dec 2020 Location: Joggins Nova Scotia Posts: 1,599	Re: 1969 or 1972 BBC alternator bracket differences thanks,my truck is coming together,i'll get you a picture of that rear rod and some measurements tomorrow when i go out to the shop,here's a picture of the rod behind the alternator hanging up after paint.the main bracket bolts to the front of the head,not the intake and the rod,to the head as well.take care.Greg Attached Images

04-29-2022, 08:23 AM	#6
mr.mud1 Registered User Join Date: Dec 2020 Location: Joggins Nova Scotia Posts: 1,599	Re: 1969 or 1972 BBC alternator bracket differences here's a couple pictures of the rear brace on the alternator of my 72 big block truck.it's hard to hold the tape and take a picture but it's about 11 inches long over all.hope that's a help.take care.Greg Attached Images

04-29-2022, 11:18 AM	#7
uncle Senior Member Join Date: Aug 2003 Location: Conyers,Ga. Posts: 7,285	Re: 1969 or 1972 BBC alternator bracket differences 68/69 bolted to front of intake. 70/71 bolted on top of intake. 68/69 also had high rise cast intake.

04-29-2022, 12:08 PM	#8
Accelo Registered User Join Date: Mar 2015 Location: washington Posts: 2,178	Re: 1969 or 1972 BBC alternator bracket differences Ok, it's becoming clearer what the differences are. Both the 68-69 and the 70-71 brackets bolted to the intake. The boss on the 68-69 intake was eliminated in 1970. So the 1970-71 bracket has the tab welded on. The attaches to one of the forward intake hold down bolts. In 1972 GM quit using any attachment bolts located on the intake and just bolted the bracket to the front of the head. The necessitated the addition of a support rod. Attached Images

04-29-2022, 10:04 PM	#9
KQQL IT At the body shop. Join Date: Aug 2009 Location: Land of fruits and nuts. Posts: 5,156	Re: 1969 or 1972 BBC alternator bracket differences Our 68 Attached Images __________________ " That didnt make it any newer " " Dont antique the equipment "



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