1973-1976 GM B body frame question

[The Continental]

Are all these years and different makes share the same frame and mounts for body and bumpers?

[Guest]

Based on earlier "B" body cars I would have to say no.

[joe_padavano]

Based on earlier "B" body cars I would have to say no.

This is not an "earlier B-body".  This is the start of GM's descent into mediocrity by badge engineering cars that were otherwise identical.  The 1973 frames are different from the 74-76 frames because the rear bumpers were only required to absorb 2.5 MPH for 73.  The full hydraulic shocks weren't added to the rear until the 1974 model year.  Otherwise, the frames are the same.  Note that the wagon frames are different from the sedan frames, however.

[Guest]

This is not an "earlier B-body".  This is the start of GM's descent into mediocrity by badge engineering cars that were otherwise identical.  The 1973 frames are different from the 74-76 frames because the rear bumpers were only required to absorb 2.5 MPH for 73.  The full hydraulic shocks weren't added to the rear until the 1974 model year.  Otherwise, the frames are the same.  Note that the wagon frames are different from the sedan frames, however.

What about front cross members that are different for each divisions engines, and what about Buicks that only use a single lower link as opposed to a lower "A" arm attachment to the frame and the tension rod mount to stabilize the Buick lower link to the front of the frame?

[joe_padavano]

What about front cross members that are different for each divisions engines, and what about Buicks that only use a single lower link as opposed to a lower "A" arm attachment to the frame and the tension rod mount to stabilize the Buick lower link to the front of the frame?

The crossmembers are identical for all divisions' engines.  The difference is the bolt-on frame pads.  The crossmember is even drilled for every possible frame mount location.  This is the same design GM used on the 1964-up A-body cars.  I don't know what a "tension rod" is, but the suspensions on the B-body (and C-body) cars are identical and interchangeable for 1971-1976.  I realize that the pre-1971 B-body cars had frame and suspension differences.  This is not the case for the 71-up cars.

[NTX5467]

Body mount location and type might be the same for MANY years of a particular body series AND wheelbase, but bumper areas might be different for the reasons mentioned above.

NTX5467

[Guest]

The crossmembers are identical for all divisions' engines.  The difference is the bolt-on frame pads.  The crossmember is even drilled for every possible frame mount location.  This is the same design GM used on the 1964-up A-body cars.  I don't know what a "tension rod" is, but the suspensions on the B-body (and C-body) cars are identical and interchangeable for 1971-1976.  I realize that the pre-1971 B-body cars had frame and suspension differences.  This is not the case for the 71-up cars.

 

The frames of 68 + "A" Body Pontiac's are wider than say 64-65. On the earlier years the track is narrower ( the upper and lower "A" arms have the same part numbers ) and if you try to install RA1-RA4 factory iron headers on the earlier cars they won't fit because of the frame. Plus the 68-73 use a 112" wheelbase and the 4dr's use a 116" wheelbase where as the earlier cars are on 115" wheelbase 2dr and 4 drs. 

Anyroad, I thought Buick still used a single lower link ( mustang style) with a tension rod to the front of the frame ( to stabilize the link ) like the early 60's  Buicks used. I believe Cadillac used this too.

[joe_padavano]

The frames of 68 + "A" Body Pontiac's are wider than say 64-65. On the earlier years the track is narrower ( the upper and lower "A" arms have the same part numbers ) and if you try to install RA1-RA4 factory iron headers on the earlier cars they won't fit because of the frame. Plus the 68-73 use a 112" wheelbase and the 4dr's use a 116" wheelbase where as the earlier cars are on 115" wheelbase 2dr and 4 drs. 

Anyroad, I thought Buick still used a single lower link ( mustang style) with a tension rod to the front of the frame ( to stabilize the link ) like the early 60's  Buicks used. I believe Cadillac used this too.

 

None of this applies to the 1971-76 cars.  The question was about the 1973-76 frames.  The 71-76 cars all used a 121.5" wheelbase. I'm not aware of any GM that used a tension rod like the Mustang, at least not in the 1960s and later.  I know for a fact that the 1971-up cars do NOT use such a configuration.

[WQ59B]

The 71-76 cars all used a 121.5" wheelbase.

My source is showing the following:

'74 Impala : 121.5"

'74 Catalina/LeSabre/88 : 124"

'74 Electra/ 98 : 127"

'74 Deville : 130"

'74 Fleetwood : 133"

[Guest]

None of this applies to the 1971-76 cars.  The question was about the 1973-76 frames.  The 71-76 cars all used a 121.5" wheelbase. I'm not aware of any GM that used a tension rod like the Mustang, at least not in the 1960s and later.  I know for a fact that the 1971-up cars do NOT use such a configuration.

 Joe, here is a picture of a 62 Buick looking at the left side toward the front. The lower arm is not a "A" arm, it is like a mustang or a Datsun 240Z. Connected to that arm or lower link there is a tension rod going to the front of the frame, this stabilizes the lower link, and mustang and 240Z also have this as well as Cadillac. see the picture; 

Edited May 20, 2015 by helfen (see edit history)

[Guest]

None of this applies to the 1971-76 cars.  The question was about the 1973-76 frames.  The 71-76 cars all used a 121.5" wheelbase. I'm not aware of any GM that used a tension rod like the Mustang, at least not in the 1960s and later.  I know for a fact that the 1971-up cars do NOT use such a configuration.

I realize that, however you said that " This is the same design GM used on the 1964-up A-body cars." and this is not true. I said Pontiac "A" body frames changed in 67, and again from 1968-1973

[NTX5467]

The frames of 68 + "A" Body Pontiac's are wider than say 64-65. On the earlier years the track is narrower ( the upper and lower "A" arms have the same part numbers ) and if you try to install RA1-RA4 factory iron headers on the earlier cars they won't fit because of the frame. Plus the 68-73 use a 112" wheelbase and the 4dr's use a 116" wheelbase where as the earlier cars are on 115" wheelbase 2dr and 4 drs. 

Anyroad, I thought Buick still used a single lower link ( mustang style) with a tension rod to the front of the frame ( to stabilize the link ) like the early 60's  Buicks used. I believe Cadillac used this too.

The "dual wheelbase" GM A-bodies were on a different body series than the '66-'67 and '64-'65 cars.  Best way to see what frame will go where is the Hollander Interchange Manual.  The GM A-cars were narrower in their first two years, then matured with the '66-'67 models (and larger motors!), and blossomed from '68 and up.

 

My '68 LeSabre has the "strut rod" front suspension, as do some Chevy B-body cars from that era.  As do my '66, '67, '70, and '72 Chrysler C-bodies.  NOT unique to "mustangs", but highly typical of so many Chrysler products with torsion bar front suspensions.

 

Regards,

NTX5467

[Guest]

The "dual wheelbase" GM A-bodies were on a different body series than the '66-'67 and '64-'65 cars.  Best way to see what frame will go where is the Hollander Interchange Manual.  The GM A-cars were narrower in their first two years, then matured with the '66-'67 models (and larger motors!), and blossomed from '68 and up.

 

My '68 LeSabre has the "strut rod" front suspension, as do some Chevy B-body cars from that era.  As do my '66, '67, '70, and '72 Chrysler C-bodies.  NOT unique to "mustangs", but highly typical of so many Chrysler products with torsion bar front suspensions.

 

Regards,

NTX5467

I posted the Buick picture because Joe said this: I'm not aware of any GM that used a tension rod like the Mustang, at least not in the 1960s and later.

But the real question is did Buick continue using this front suspension in 1971-76?