68 frame Qs
Thread Starter
Drifting
Joined: Apr 2014
Posts: 1,766
Likes: 78
From: montague michigan
C2 of Year Finalist (stock) 2019
68 frame Qs
hey guys, i just picked up a 68 roadster. the frame is scaly and i am not sure yet what i am going to run into. i am up on c2 stuff, but its been a while since i worked on or/owned a c3. so what is the differences in frames on a c3? i assume 68-72 are the same. but what changes later? can they be modified to work in a 68-72? are convertible frames the same as coupes? if i need one, are there any good frames out there? give me your thoughts guys...thanks troy
Racer
Joined: Mar 2009
Posts: 276
Likes: 31
From: Brant County Ontario
IIRC
The early 68's and the later 68's are different. There's additional support on the late 68 frames that carried through to later years.
Late 68 to 73 should be the same (or very close, anyway). 74+ had changes to the rear to accommodate the 5mph bumpers. I believe in '75 the front end of the frame was altered. Then in (I think) '80 the rear suspension mounts change.
Don't quote me on this though.
The frames are all pretty similar to the C2 stuff though, you should feel more or less at home.
The convertible and coupe frames are the same (if I am not mistaken). As to using a much later frame - I'm swapping a 69 frame under my 73. Side by side, with the front bumper braces removed, they're extremely similar if not totally identical. Later ones would be a bit more work because of the rear bumper changes.
Just like in a C2, the birdcage is what you REALLY want to inspect.
Aftermarket options:
http://www.sriiimotorsports.com/196382corvette.html
https://www.streetshopinc.com
http://roadstershop.com/product/full...vette-chassis/
Literally the first 3 hits I had on google. I knew about the SRIII but haven't used any of these myself. Others can chime in on options who are better suited to doing so than I.
The early 68's and the later 68's are different. There's additional support on the late 68 frames that carried through to later years.
Late 68 to 73 should be the same (or very close, anyway). 74+ had changes to the rear to accommodate the 5mph bumpers. I believe in '75 the front end of the frame was altered. Then in (I think) '80 the rear suspension mounts change.
Don't quote me on this though.
The frames are all pretty similar to the C2 stuff though, you should feel more or less at home.
The convertible and coupe frames are the same (if I am not mistaken). As to using a much later frame - I'm swapping a 69 frame under my 73. Side by side, with the front bumper braces removed, they're extremely similar if not totally identical. Later ones would be a bit more work because of the rear bumper changes.
Just like in a C2, the birdcage is what you REALLY want to inspect.
Aftermarket options:
http://www.sriiimotorsports.com/196382corvette.html
https://www.streetshopinc.com
http://roadstershop.com/product/full...vette-chassis/
Literally the first 3 hits I had on google. I knew about the SRIII but haven't used any of these myself. Others can chime in on options who are better suited to doing so than I.
Last edited by davidchristopher; Aug 13, 2018 at 01:03 AM. Reason: More stuff
Pro
Joined: Apr 2012
Posts: 657
Likes: 114
From: Picton NSW
YOU will find the C2 frame and C3 are just about identical from the front to the kick up area. at the rear of the frame.
The C2 and C3 main difference generally speaking starts about 18" to the rear of the trailing arm pivot point.
when fitting say and 1980 frame under a 68/72/3 then just crafting the rear section behind the rear diff mount cross member is the main alteration you need.
along with some welding/fabricating skills and the ability to use a tape measure .
this is not a job for a novice.
PS the roadster shop frame is impressive
The C2 and C3 main difference generally speaking starts about 18" to the rear of the trailing arm pivot point.
when fitting say and 1980 frame under a 68/72/3 then just crafting the rear section behind the rear diff mount cross member is the main alteration you need.
along with some welding/fabricating skills and the ability to use a tape measure .
this is not a job for a novice.
PS the roadster shop frame is impressive
Last edited by bfit; Aug 13, 2018 at 01:18 AM.
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
If you need a frame, David. Allvettesforme on here. He is a cross between hobby and business frame restorer. He just broke a foot and has decided to down-size. He currently has 3 or4 frames he wants to unload. PA to you shipping will be a pain, but worth looking into.
Thread Starter
Drifting
Joined: Apr 2014
Posts: 1,766
Likes: 78
From: montague michigan
C2 of Year Finalist (stock) 2019
If you need a frame, David. Allvettesforme on here. He is a cross between hobby and business frame restorer. He just broke a foot and has decided to down-size. He currently has 3 or4 frames he wants to unload. PA to you shipping will be a pain, but worth looking into.
it has been in this storage unit since 1990. when i loaded it on the flat bed the PO said it is the first this car has seen daylight since he put it in there.
Thread Starter
Drifting
Joined: Apr 2014
Posts: 1,766
Likes: 78
From: montague michigan
C2 of Year Finalist (stock) 2019
If you need a frame, David. Allvettesforme on here. He is a cross between hobby and business frame restorer. He just broke a foot and has decided to down-size. He currently has 3 or4 frames he wants to unload. PA to you shipping will be a pain, but worth looking into.
Team Owner
Joined: Jul 2004
Posts: 40,404
Likes: 791
From: Redondo Beach, California
hey guys, i just picked up a 68 roadster. the frame is scaly and i am not sure yet what i am going to run into. i am up on c2 stuff, but its been a while since i worked on or/owned a c3. so what is the differences in frames on a c3? i assume 68-72 are the same. but what changes later? can they be modified to work in a 68-72? are convertible frames the same as coupes? if i need one, are there any good frames out there? give me your thoughts guys...thanks troy
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Administrator
Joined: Jul 2000
Posts: 53,982
Likes: 6,209
From: About 1100 miles from where I call home.
When you could buy a new C3 frame from GM, the 1973 frame was used as a service replacement for the 68's through 72's. When you go to bolt on one of the frame extension "horns"...the brackets that attach to the far ends of the front chrome bumper, the 68's through 72's will require an extra hole to be drilled to fasten the frame extension horn. How do I know this? I ordered a 69 frame from GM Parts in 1981. A few years ago, I was bewildered that my 70 frame extension horns didn't quite match up to the frame and I could see my 68 horns wouldn't fit either. I knew the 68 horns should fit a 69 frame. Eventually someone at the Corvette vendor, Volunteer Vettes, explained the mystery to me....my order of a 69 frame resulted in me getting a 73 frame.
hopefully he’s figured it out after 5 years.