1966 Acadian Rear Diff Width

Passion · Member

1966 Acadian Rear Diff Width

tc · Guru

The usual width is 52-53 inches. Yes the high performance cars from 275HP. and up came with the 12 bolt.

Passion · Member

Ya that is about what it measures

That is cool I didn`t know any of these came with a 12 bolt

So what was 275hp and up were they all 327 or did they have a 275hp 283 ?

Thanks for the reply

Beaumont4008 · Uber Guru

Just looking in the 66 brochure and only lists three engines. Seems hard to beleive that no lower performance 327 was available. Any Acadian experts out there that could verify if this is true ? Maybe yours is a L79 car. Or could the 12 bolt be ordered with the 283 ?

120-HP ECONOFLAME 6; 194 cu.-in. displacement, compression ratio 8.5:1. Uses regular fuel.

195-HP ECONOFLAME V8; 283 cu.-in. displacement, compression ratio 9.25:1. V8 performance and high economy. A full-flow oil "filter, positive crankcase ventilation and an oil-wetted paper element air cleaner are other features. Two-barrel carburetion.

350-HP SUPER ECONOFLAME V8; 327 cu.-in. displacement. The compression ratio is 11.0:1, carburetion 4-barrels.. Hydraulic valve lifters are standard on the 327 V8.

Passion · Member

Thanks for the info

I am crossing my fingers that it just might be, I was really surprised to find a 12 bolt in it and it does not appear to have been modified and put in brackets etc, look like stock type welds etc.

Have to do the GM Documentation this week....not knowing is eating at me

Thanks again for your help

tc · Guru

275 HP. and up were all 327's. Although i've never seen one it is not impossable that you could't order a 12 Bolt with a 283.

427carl · A Poncho Legend!

My neighbors 67 Chevy II and his sons Chevy II have "original 12 bolts" both cars were 327-275HP

On the 66 Acadian race car (they call it a 67 Chevy II ) they ran a full size rear from a 68 Impala and used steel FWD Toro. rims to fit slicks

Beaumont4008 · Uber Guru

Just from reading the brochures on file, the 275 hp 327 was new for 67 and not available for 66. 67 had the 250 and 275 hp 327 options. 66 had only one 327 option the 350 hp. Looks like 66 was kind of a strange year for engine optons. 66 had only three engine options(1 six a 283 and a 327) while the 67 had 5. (2 ea six's a 283 and 2 ea 327's) .

I just find it interesting that 65 and 67 had 5 engine options while 66 had only three. Just wondering what happened in 66 for that to happen ?

-- Edited by Beaumont4008 on Sunday 18th of July 2010 11:55:31 AM

Passion · Member

Thanks for the replies
Engine options for 66 is interesting
Back years ago the guys that had it were pretty hardcore hippies, not that I wasn`t but I am not sure they would`ve known a 283 from a 327 or looked into it................so I am going to see if I can find any dates or markings on the diff....going to have to send for gm docs, driving me a little bonkers not knowing............funny before didn`t seem to matter what it was now my curiosity is killing me

Thanks for all the replies

427carl · A Poncho Legend!

If you are looking for a proper, original Chevy II 12-bolt, they are as rare as hen's teeth.

The 12-bolt in the early Chevy II only came in 1965 327 cars (they made 319 with 300 horse)

and 1966 Chevy II & Acadians with L-79 power under the hood (3.07 with 3-speed Saginaw, 3.31 or 3.55 with 4-speed Muncie

427carl · A Poncho Legend!

Passion wrote:

Hi
Can anybody tell me what the width should be of the rear diff in a 66 Acadian ?
Say backing plate to backing plate ?
And did any come with a 12 bolt ?

Picked up a project car 66 SD and it has a 12 bolt in it

Thanks for any help

57.75	1962-1964	Chevy II/Nova
57.75	1965-1967	Chevy II/Nova
58.00	1978-1988	Chevy Malibu, Monte Carlo
59.50	1968-1982	Corvette
60.00	1955-1964	Chevy Car
60.00	1967-1969	Camaro
60.25	1968-1979	Chevy II/Nova
60.50	1984-1995	Corvette
60.50	1964-1967	Chevelle
62.00	1955-1959	Chevy Pickup
61.25	1968-1972	Chevelle
62.50	1970-1981	Camaro/Firebird

Beaumont4008 · Uber Guru

Should be some letters and numbers stamped on the passenger side axle tube that can help date the diff and identify if for a acadian/chevy ll car. Also the casting number on the centre section might help.

68sd · Canadian Poncho Superstar!

would the L-79s be only 3 and 4 speed cars?

Optional * 350-hp Super Econoflame 327	All Models and Series	3-Speed	3.07:1	N.A.

		4-Speed	3.31:1	N.A.

what does your cowl tag say ,does it say M35?

-- Edited by 68sd on Sunday 18th of July 2010 01:29:23 PM

Passion · Member

Yes my cowl shows M35 so it would appear a glide

Rear end appears the right width but...
But I see the main brake line cut on the diff and the one in the car appears in tacked so I will try and find codes but I am thinking maybe it was swapped in,but if it was they didn`t move the leaf brackets so it must have come from a very similiar body style also on the pass side of diff on the lower tube I see a braket has a cut rod with bushing in it still, but I would assume it was some type of traction bar from the factory in whatever vehicle the diff come out of I looked quickly but see no brackets on the frame were such a bar may connect to

Anybody known anything about such a factory bar traction type looks factory weld etc. ?

Thanks again for all your help

Part was hoping L79 car (don`t think so though) but the other part not.....then I can just build it the way I want....if it was L79 in my mind I would be forced to period correct restore

Thanks Again

ARCADIAN · Poncho Master!

No powerglide L79 car

ARCADIAN · Poncho Master!

At least not in an Acadian or Nova

4SPEED427 · A Poncho Legend!

One thing you can check is the fuel line from front to back. A 283 car in 66 would be 5/16" and a 66 Acadian 327 car would be 3/8" inch since as stated, the 327 car would have to be an L79 car.

And as stated, I don't think GM ever offered an L79 in front of an auto trans even in a Corvette. Certainly not in a Nova/Acadian.

If you still need a measurement, I can get it off a 65 diff I have sitting here (10 bolt that is!) but it should be the same as a 12 bolt.

-- Edited by Carl Stevenson on Tuesday 20th of July 2010 11:17:13 PM

Passion · Member

Thanks Carl

I will check the fuel line that si a good idea
Ya diff measurement should be the same Don`t think this one is factory but if it fits right then perfect I might just be asking for a few meaurements I should pull wheels and do a full width measurement

Thanks for the reply
Thanks for showing me how to add a pic on the other post too

4SPEED427 · A Poncho Legend!

No problem, you're welcome. Post up whatever you have questions about and somebody here will likely be able to help.

I am planning to build an "original" 12 bolt for my 65 some day. I have all the correct pieces, just need to bump it up the priority list...

Beaumont4008 · Uber Guru

Here is some info for you, should be the same for Acadian.