I have the following 1970 Chevelle BB A/C brackets.

1970 Chevelle BB A/C Bracket Numbers
Bracket-RR: 3969911
Support-RR: 3969912
Support-FRT: 3969917
Bracket-FRT: 3969916
Brace-Rear:3969910

What are the differences (if any) of the following 1969 Chevelle BB A/C brackets in comparison to the 1970 A/C brackets? EDITED 5-17-06: The following are part numbers obtained from someone selling '69 A/C brackets some time ago on TC. Responses so far indicate '69 & '70 are the same so what would the part numbers below be? 71 on up? Or are the part numbers above that I have '71 on up? I have pics of mine and will post later on.

1969 Chevelle BB A/C Bracket Numbers
Bracket RR: 3932493
Support-RR: 3940946
Support-FRT: 3940948
Bracket-FRT: 3940949
Brace-Rear: 3940947

One last thing... what are the part numbers for 1971 and 1972 Chevelle BB A/C Brackets? What are the similarities to the '69 and/or '70 Chevelle BB A/C brackets? And why are the '71 & '72 BB A/C brackets apparently so hard to find?

Thanks for any information anyone can provide.

ttt
Anyone?

the 1969 and at least the early 1970 big block A/C brackets look the same, I do not know when the change took place I have the original brackets on my car I dont know the part # s but they look like the 69s, my car was built on 12/30/69 at the kansas plant,but I have seen many 70s with the brackets that look like the 71 and 72s? maybe someone with a 71 or 2 can tell you more about them, Marty

If I remember, the '70s had a solid bracket on top with a hole for the PCV valve. The '71-'72s are shaped like a leaning "V" with a large open area. I don't know about the others.

The 69-70 brackets are the hard ones to find and expensive. The 71-up are common. I think the GMC and Chevrolet trucks with Big blocks used the same brackets from 71-76??

Here's a pic of the A/C brackets I started this topic with.

http://www.chevelles.com/showroom/showphoto.php/photo/5987/cat/500/ppuser/1185

the picture of the brackets you have are the 71,72 style but like I said I have seen 70 with those? maybe later production? different plant? I know the ones I have or like the 69 on the top rear bracket, Marty

Those are 71-up, they do the job they are intended for, for any big block with a long water pump in any vehicle application be it a car or truck. Very few people will know or care really that they are not the "correct" ones for 1969-1970.

Here is a set of the AC brackets that are very hard to find. And date coded.
http://img208.imageshack.us/img208/1359/ac0bi.jpg

A/C brackets are date coded? I know they have part# but where are the date codes? thanks, Marty

Here is one with a date code on it.
http://img198.imageshack.us/img198/6213/acbracketwithdates7yi.jpg

Thanks to all that replied to my post, and to those that replied via private e-mail. I was attempting to figure out the application of the brackets I have. 1badss396, can you please list the part numbers for the A/C brackets pic you provided? I'd appreciate it.
Are they the part numbers I provided in initial post? Looks like of of them is (3940948) Bracket RR: 3932493 Support-RR: 3940946 Support-FRT: 3940948 Bracket-FRT: 3940949 Brace-Rear: 3940947