The holes for the bumper mounts for the 72 aren't on the 74 frame. It can be done (I did it for my 73) but there is some mods required to make it work
Frame difference 72 vs. 74??
Thread Starter
Instructor
Joined: Dec 2006
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From: Crystal Lake Illinois
The 72 I have is a complete car. Would all the bumper mounts off the 72 bolt onto the 74 frame? I know the headlight vacum canister on the 74 is up front, but as mentioned the 72 is a complete car, so I could swap anything over. Before I get to far into this, just trying to find out what I will run into.
Melting Slicks
Joined: Oct 2002
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From: I may be getting old but I refuse to grow up
Burning Brakes
Joined: Jan 2009
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From: Clarksville Indiana
I did not know what year frame is under my 71, but I just found out it may be a 74 as I have issues with the holes and getting the front back together. I seem to have some clearance issues with frame top edge and radiator also.
Thread Starter
Instructor
Joined: Dec 2006
Posts: 116
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From: Crystal Lake Illinois
OK, so are you saying the rear is fine but I will need to make a template of the 72 front frame horns and drill a few holes......or is there more to it than that?
Does anyone have some good pics of their 72 frame so I can compare to my 74 frame?
Does anyone have some good pics of their 72 frame so I can compare to my 74 frame?
Safety Car
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From: North Easton Mass
Rick B.
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I think the correct explanation is that "you will have to redrill the holes in the frame extentions." I think the bumper brackets will work as is.
In the early 80's I ordered a 69 frame from the GM parts department of a local dealer. In due time I received my "69" frame. I kept it stored until a few years ago I decided to use it. I'm building it up and planning on dropping the body of my 70 on it. No problem I thought since the 69 and 70 frames are identical. Opps! the 70 frame extentions didn't mount up properly. I tried frame extentions from a 68 (they are a little different also) No luck. I called Volunteer Vette and they verified that the 70 had the same extentions that a 69 would have. A trip to J & D Corvette and they were bewildered....why didn't the 70 frame extentions fit? A post on the NCRS website answered my question. In 1974, and thereafter, if you ordered a 68,69,70,71,72,73 frame from GM, they would ship you a 74 frame. 74 frames became the service replacement. I'd guess the 72 has the same frame extentions as a 70 so this is where you'll have a mismatch.
In the early 80's I ordered a 69 frame from the GM parts department of a local dealer. In due time I received my "69" frame. I kept it stored until a few years ago I decided to use it. I'm building it up and planning on dropping the body of my 70 on it. No problem I thought since the 69 and 70 frames are identical. Opps! the 70 frame extentions didn't mount up properly. I tried frame extentions from a 68 (they are a little different also) No luck. I called Volunteer Vette and they verified that the 70 had the same extentions that a 69 would have. A trip to J & D Corvette and they were bewildered....why didn't the 70 frame extentions fit? A post on the NCRS website answered my question. In 1974, and thereafter, if you ordered a 68,69,70,71,72,73 frame from GM, they would ship you a 74 frame. 74 frames became the service replacement. I'd guess the 72 has the same frame extentions as a 70 so this is where you'll have a mismatch.
Burning Brakes
Joined: Jan 2009
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From: Clarksville Indiana
Heres a pic that shows some of the issue with the frame ends and the second pic shows the issue with the radiator hitting the frame. I went down to Willcox and looked at a 71 and the very end of the frame is cut off at a angle and the frame in the pic it is cut off square and the radiator hit the corner of it.
Last edited by 71coupe454; Apr 23, 2010 at 02:33 PM.
Melting Slicks
Joined: Oct 2002
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From: I may be getting old but I refuse to grow up
The rear is probably fine. There were some plates added for crash bumpers that may or may not need to be removed. If you hold your 72 front bumper mounting plates up to the 74 frame you will see which holes line up and which ones will have to be drilled or elongated. I would modify the mounting plates rather than the frame since the metal is much thinner on the mounting plates.
Rick B.
Rick B.
This is a shot of the rear of a 74 frame
And after but before I drilled the holes for the bumpers
