Not all G Body frames are the same

[beststeak]

I am trying to pinpoint EXACTLY what year make and model the G Body FRAMES have an OVAL HOLE in the frame where the lower rear trailing arm attaches to the frame. Most everything cross references as being the same but they are NOT THE SAME!
So far my list includes ONLY the following as having this particular hole:
1978 Malibu
1979 Malibu
But that is as far as I have gotten. I have been told that more than likely this will only be found on 1978 and 1979 cars. Yet the frame specs show they are the same from 78 through 83ish. I race these cars on dirt and this OVAL HOLE in the frame is the signature to something else different on the car but the car builder will not tell me what that difference actually is. So I am in search of a metric frame with this hole it. The problem is finding which cars have it and which don't. I did some searching and found this forum and it looks pretty active (most forums these days are dead) So I am asking you good people in hopes someone out there can help me in my search. I will post a couple of pictures of said hole so we all understand what I am looking for. Help me if you can so I can eliminate makes and models from list or even more importantly if you have one send a picture of it so I can INCLUDE it to the list. And if you happen to know someone who has one of these frames for sale close to the Middle Tennessee area pint me in their direction. Thank you!

 

[Merlin1952]

I have a 1978 Pontiac Grand LeMans that has those oval holes.

 

[79 USA 1]

I have a pair of 1979 Monte Carlo's, Both have the oval hole. I remember my 79 Malibu Classic and 86 El Camino also having the oval holes as I replaced rear control arms in both.
Looking at the 1988 Monte Carlo SS T-Top car it has the circular hole.
The frame differences I understand were the 1978-1980 3rd gen Monte Carlo and maybe the Grand Prix (A-Specials) having a longer front frame rails from the radiator core support to the bumper mount flange. The rear portion of the wagon and El Camino frames due to different body mount location and the El Camino having a longer wheel base which lengthened the center of the frame.
Now I'm curious if the T Top cars were different to eliminate some of the flex due to the weaker roof structure.

 

[pagrunt]

Here's an older posting of mine on frame p/n interchange. Not 100% complete but enough info to show what can interchange

• Nov 8, 2017
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• #15

This is what I found usimg my Chevy parts books.
Monte Carlo frame p/n: '78 470211, '79 14017671 (must use engine mount 14005699 on '78 models) (used on '78-'81 Buick 09, 69, 87), '80-'81 14013462 (superseded '78 & '79 p/n's) (used on '81 Regal), '82-'88 14103516 (use on '83 Olds W40 Hurst/Olds, '78-87 Pontiac except 35.)
Malibu (19, 27, 69) p/n: '78 461808, '79 14005602 (same note as Monte Carlo), '80 14017667 (must use '80 front park brake cable on earlier models, superseded '79 p/n) (Used on Buick 09, 69, 87), '81 14032514 (superseded '78-'80 p/n's.)
Note body codes:
2 door body: 27, 37, 47, 87
4 door body: 09, 19, 69
station wagon: 35
Looks like the Monte frame would be the one to work on a LeMans. Keep in mind that this is incomplete as I have not cross checked all GM catalogs for our cars.

 

[303'505rollin]

I'll check my 81 monte

 

[69hurstolds]

Here's an older posting of mine on frame p/n interchange. Not 100% complete but enough info to show what can interchange

• Nov 8, 2017
• Add bookmark
• #15

This is what I found usimg my Chevy parts books.
Monte Carlo frame p/n: '78 470211, '79 14017671 (must use engine mount 14005699 on '78 models) (used on '78-'81 Buick 09, 69, 87), '80-'81 14013462 (superseded '78 & '79 p/n's) (used on '81 Regal), '82-'88 14103516 (use on '83 Olds W40 Hurst/Olds, '78-87 Pontiac except 35.)
Malibu (19, 27, 69) p/n: '78 461808, '79 14005602 (same note as Monte Carlo), '80 14017667 (must use '80 front park brake cable on earlier models, superseded '79 p/n) (Used on Buick 09, 69, 87), '81 14032514 (superseded '78-'80 p/n's.)
Note body codes:
2 door body: 27, 37, 47, 87
4 door body: 09, 19, 69
station wagon: 35
Looks like the Monte frame would be the one to work on a LeMans. Keep in mind that this is incomplete as I have not cross checked all GM catalogs for our cars.

Keep in mind that GMSPO part numbers are AFTER the fact. Sure, they do their best to say this part fits this or that, but sometimes it's not always the case. I'm not saying the frame part numbers aren't correct, but they usually don't tell you what is different, if anything, on the parts. Sometimes they do, like if you used that 79 frame on a 78, you had to use certain motor mounts.

Now- unless you were doing a meticulous frame-off, I'm failing to see why anyone would care if you have an oval hole or a round hole in that location. If you need an oval hole for something specific, couldn't you cut it out?

Digging into some part numbers, you could EVEN buy a front section of the frame including the crossmember. P/N 14034875.

The seemingly uber-frame p/n...

14103516

How did we get here...

Superseded part numbers are the name of the game. For example, the 14103516 had several predecessors. While some things may be different from frame to frame, it should interchange with no or minimal modifications.

14005606(79 Malibu and several others)->14017671->1403462->14103516

472111(78 Mailbu and several others)->14017671->1403462->14103516

14077757->14085304->14103516

14073026->14059167->14085304->14103516

To add, the 78 A19-27 used the above mentioned 14005602, but was superseded by several other part numbers landing on 14032514 which that one in itself went disco'ed 31 years ago! I do not know what difference there was to these frames that they weren't listed as interchangeable with the A37.

14005602->14017667->14013461->14032514

And then for 78 A19-27, it also lists a 461808, which superseded by...you guessed it...14032514. WTF?

It can get confusing...fast.

 

[L92 OLDS]

Another one of those circle track guys 🙄.I don’t necessarily like what circle track racers do to G bodies. 🤭. I was at a pic and pull yard near Louisville a while back. In a matter of an hour these guys cut 3 nice rust free G bodies in half with a sawzall. Yes, I understand these cars were ready for the crusher but these guys are likely buying up restorable cars elsewhere and destroying them. Not what I would call bringing them back to life and saving the hobby. You’re probably a great person though. Welcome to the forum. Why is the oval hole so important to you?

 

[78Regal350]

My ‘78 Regal has the oval holes.

 

[grandamman]

I havent checked mine yet, but am also curiouse of the importance of the oval hole.

I am in East TN and am starting to piece out several parts cars.

 

[79 GP 4 speed]

Curious about the hole also