Question about frame differences,..1973
Thread Starter
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
Question about frame differences,..1973
I'm looking to purchase a 1973 convertible project but the frame on the car has been sliced and spliced just below the front door.
I would want to set her on a good "one-piece" frame. There's a few frames out there for sale with reasonable pricing (I know, the words "reasonable" and "Corvette" are never to be used in the same sentence).
But I don't know which year frames would be a direct swap for the 73. I do know I'd need a 4-speed frame if anybody has a line,..let me know.
Please advise,...thanks!
Wes
I would want to set her on a good "one-piece" frame. There's a few frames out there for sale with reasonable pricing (I know, the words "reasonable" and "Corvette" are never to be used in the same sentence).
But I don't know which year frames would be a direct swap for the 73. I do know I'd need a 4-speed frame if anybody has a line,..let me know.
Please advise,...thanks!
Wes
Safety Car
Joined: Aug 2001
Posts: 4,883
Likes: 11
From: North Easton Mass
Originally Posted by 73, Dark Blue 454
I'm looking to purchase a 1973 convertible project but the frame on the car has been sliced and spliced just below the front door.
I would want to set her on a good "one-piece" frame. There's a few frames out there for sale with reasonable pricing (I know, the words "reasonable" and "Corvette" are never to be used in the same sentence).
But I don't know which year frames would be a direct swap for the 73. I do know I'd need a 4-speed frame if anybody has a line,..let me know.
Please advise,...thanks!
Wes
I would want to set her on a good "one-piece" frame. There's a few frames out there for sale with reasonable pricing (I know, the words "reasonable" and "Corvette" are never to be used in the same sentence).
But I don't know which year frames would be a direct swap for the 73. I do know I'd need a 4-speed frame if anybody has a line,..let me know.
Please advise,...thanks!
Wes
Unless you are really concerned about originality an auto trans frame with the removable crossmember is much easier to deal with in terms of transmission removal and replacement.
Rick B.
Burning Brakes
Joined: Nov 2004
Posts: 899
Likes: 1
From: Kansas
I have read on old posts that the front of 68-74 frames are the same but the 74 rear are different and 68-72 the body mounts are higher or lower on the frame ,because of 73 using rubber mounts instead of the solid mounts the 68-72 used.
I used a 74 frame on a 73 vert I'm working on,cut the rear about 16" off the 74 and used the old 73 section ,welded back on.
I used a 74 frame on a 73 vert I'm working on,cut the rear about 16" off the 74 and used the old 73 section ,welded back on.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Originally Posted by 73, Dark Blue 454
Does any body know if the big vacuum reservoir in the front of 73's and 74's (the big cylindrical tank that sits parallel to the front bumper) will fit on a 68-72 frame?
Your much better off modifying a 68-72 frame to fit a '73 than a '74-'82.
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Pro
Joined: Aug 2003
Posts: 530
Likes: 0
From: Victoria Texas
I have a good bare frame from a 75 I will sell.
I parted the car many years ago and the frame is still sitting behind my shop.
You will have to change the rear bumper mounts, I have done this to one before.
I think the 78 and up frames have the gas tank crossmember moved .
I am South of you in Victoria.
Thanks, Mark G gregurek@***.net
I parted the car many years ago and the frame is still sitting behind my shop.
You will have to change the rear bumper mounts, I have done this to one before.
I think the 78 and up frames have the gas tank crossmember moved .
I am South of you in Victoria.
Thanks, Mark G gregurek@***.net
Thread Starter
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
Mark,..thanks neighbor, but for the time being I'll attempt to hold out for a 73 or earlier frame. It sounds like using a post-1973 frame requires welding in the rear. A pre-73 frame requires the drilling of a couple of holes in the front frame horns,..I think.
BTW,..I did a couple of years in Corpus in the early 90's,..great area!
BTW,..I did a couple of years in Corpus in the early 90's,..great area!
Melting Slicks
Joined: Aug 2006
Posts: 3,429
Likes: 20
From: Kingston Ontario
Differences
I'm doing the swap now. Someone at one point put a spliced together frame under my 72, a late 74 and up frame(it's for sale by the way, not rusty). The frame you see here is a 73, it's exactly like a 72. As previously mentioned , the differences to new frames are, other than the rear differences,the holes on the frame horns are different and the proportioning valve on the 73 is mounted vertical closer to the front left A-arm rather than horizontally further down the frame rail.
Burning Brakes
Joined: Aug 2006
Posts: 1,217
Likes: 5
From: Stark County Ohio
An automatic frame will work just fine if you are not a stickler for keeping the car as “original” frame wise. The removable cross-member is in the exact same place as the welded in cross-member of the 4-speed frame. The benefit of using the automatic frame is that it provides a little easier access for transmission removal, since the cross-member can be removed.
Welding the last few inches onto a later model frame is not difficult and will not compromise the strength of the frame. This could save you a LOT of money AND provide you with a much larger selection of “rust free frames”.
Take your time in your search finding a high quality frame. Don’t settle for “junk”.
One thing I am NOT sure of is the height difference of the body mount brackets on the frame between the 72 (thinner metal body mounts) and 73 & up (thicker rubber body mounts), but I suspect that they are the same.
I own a couple of 72’s and four 74’s and the 72’s sit lower on the frame compared to the 74’s simply by observing the rocker panel under the doors. You can see more of the frame itself on the 74’s indicating that they sit maybe ¾ inch higher on the frame. My cousin has a 73, which sits the same as my 74’s on the frame.
Welding the last few inches onto a later model frame is not difficult and will not compromise the strength of the frame. This could save you a LOT of money AND provide you with a much larger selection of “rust free frames”.
Take your time in your search finding a high quality frame. Don’t settle for “junk”.
One thing I am NOT sure of is the height difference of the body mount brackets on the frame between the 72 (thinner metal body mounts) and 73 & up (thicker rubber body mounts), but I suspect that they are the same.
I own a couple of 72’s and four 74’s and the 72’s sit lower on the frame compared to the 74’s simply by observing the rocker panel under the doors. You can see more of the frame itself on the 74’s indicating that they sit maybe ¾ inch higher on the frame. My cousin has a 73, which sits the same as my 74’s on the frame.
Thread Starter
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
Timemender,..thanks for the input. You have me thinking. If I go with a Pre-73 frame, I'd planned to use the Pre-73 body biscuits. You believe no changes were made to the frame to accomodate for 73's thicker body biscuits. Hmmm. I'd like to use a 73 or earlier frame but keep my rubber biscuits for ride quality.
Interesting and counter to what some believe.
Can anybody second Timemender's opnion?...I hope he's right!
Thanks!
Wes
Interesting and counter to what some believe.
Can anybody second Timemender's opnion?...I hope he's right!
Thanks!
Wes
Racer
Joined: Jul 2001
Posts: 361
Likes: 9
From: Dresser WI
I mounted a 77 frame under my 73 the only change was the last 16'' in the back i removed the rear part off of the 73 and installed them on the 77. The rear of the 73 was 3/8'' taller then the 77 but i was able to weld it together and it's not visable. The 77 frame i purchased was $162.00 and change shipping from tx to wi was $250.00 no other problems. John