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Are the frames for 70-77 vettes all the same?
Also, are the motor mounts the same for a big and small block?
I just picked up a 74 matching numbers big block car, but it needs a frame. I know there may be some minor differences, but I thought they were all basically the same.
Thanks for your help!
Sorry, my bad,
Without over detailing, 68 to 72 with chrome.bumpers have different frames the ends than 74 up to 80, 73 i think is unique and i believe they changed with batwing rears in 80,
If you have a 74 then 74 75 would be best but then 76 to 79, will work
68 to 72 isnt wirth the extra work ,
My 69 has a 68 frame,
Others will chime in with more details
Last edited by The13Bats; Sep 16, 2018 at 10:02 PM.
1968-1972 are the same.
1973 is different up front, same rear as 72.
1974 is different up front and in the rear.
1975 same front as 74, different rear.
1976-1978 same front, different rear.
Looks like I got the one year that is unique. That’s what I get for wanting a big block.
Its just has to do with bumper and or crash stuff mounting,
You can mod a 75 to 79 frame to work
Bb chassis are the same, some bb suspension parts are beefier,
On my 69 my 68 chassis i had to add rear reinforcements etc
1968-1972 are the same.
1973 is different up front, same rear as 72.
1974 is different up front and in the rear.
1975 same front as 74, different rear.
1976-1978 same front, different rear.
Looks like I got the one year that is unique. That’s what I get for wanting a big block.
Unless there is an easy mod?
I went through this while looking for a replacement frame for a 69 . From what I discovered on this forum by reading dozens of threads ,was at one time GM sold the 74 frame as a replacement for the earlier c3 frames.
I ended up getting a 78 frame to replace a 69 and have just started getting it to fit , at the front it's just a matter of adding two extra holes in the 69 extensions to match the bolt pattern in the 78 chassis. I think your crash bumper "battering ram " is the equal to the 69 extensions , but its the same fix . As for the back I will just make the pieces fit when I get to it !
Believe me I tried and tried to get a 68-72 frame so hard to avoid all this but they are worth their weight in gold now, mostly because as soon as the seller realised where I was the shipping cost went through the roof . You being more local will have better luck finding one for a reasonable cost.
That' a 69 extension , someone (Not me ) already opened those original holes .My car was badly smash repaired before I got it. The white marker is my wor k at where the new holes went to make it fit on the 78 frame !..
Hi, I have done many frames, for the 68-72 I just keep the old rusted unit cut off last 3 feet and weld to newer frame, usually the rust frame is bad in the middle and where the swing arm attaches, a good sandblast solves the problem
with the back 2-3 feet, very easy to weld and "hide" the changeover, any good welder can do this, easy alignment. Mike.
It sounds like the front is the same, just use my existing crash bar and bolt onto the frame ends. Any idea what it would take to get the rear to work? If I can sit the 74 body on it, and adjust that, or would I need to cut and weld the back half, which I really don't want to get into.
How about the body mounts, are they all in the same locations?
Thanks again everyone for the help. I found a 70 frame I would really like to make work as it is ready to go, but don't want to buy it and it end up being useless for my.
[QUOTE=jsbwac;1597998363]It sounds like the front is the same, just use my existing crash bar and bolt onto the frame ends. Any idea what it would take to get the rear to work? If I can sit the 74 body on it, and adjust that, or would I need to cut and weld the back half, which I really don't want to get into.
BODY mounts exactly the same, very very easy to cut back part and weld, a small mig wlder (wire feed) is what I use, weld the heck out of it, grind, reweld parts missed, grind again, a small amount of putty to hide scratches and no one will know,
honestly 6 hours work, . attached is a pic of one I did last year, sorry, but do not have pic of welded area, just finished, this is a daily driver guys , so did not go to crazy. made up 71
It sounds like the front is the same, just use my existing crash bar and bolt onto the frame ends. Any idea what it would take to get the rear to work? If I can sit the 74 body on it, and adjust that, or would I need to cut and weld the back half, which I really don't want to get into.
How about the body mounts, are they all in the same locations?
Thanks again everyone for the help. I found a 70 frame I would really like to make work as it is ready to go, but don't want to buy it and it end up being useless for my.
Detailed information sent to you at 3:30 pm yesterday. If you have that 70 frame detailed out as I have described then great. I have had too many frames, and folks, find twisted and bent frames that were media blasted and POR-15 coated, painted, and powder coated, only to realize they are not within specifications when they tried to use them. If you pass on the 70 frame I might be interested in checking it out as well, would appreciate a lead on it as I am only across the river in PA.
Good luck with your decision and best regards,
David Howard
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