Frame swap on early C3 cars - CorvetteForum - Chevrolet Corvette Forum Discussion


C3 General General C3 Corvette Discussion not covered in Tech
Sponsored by:
Sponsored by:

Frame swap on early C3 cars

Reply
 
 
 
Thread Tools Search this Thread
Old 09-08-2005, 01:52 PM   #1
chevy69
CF Senior Member
Thread Starter
 
chevy69's Avatar
 
Member Since: Aug 2005
Location: Chandler Arizona
Posts: 3,654
Thanks: 0
Thanked 0 Times in 0 Posts
St. Jude Donor '08
Default Frame swap on early C3 cars

Greetings from Still very HOT Phoenix. I have a '69 coupe, SB, 4Spd car I am going through. Although I think I can clean the rust in my frame (in rear - typical areas) up fairly well, I found a guy last week that offered me a frame (off a '74 or '76 not sure which) that had been tweaked in the front for $200. He said I can take all or part for that price, and it appears to be straight from the firewall back (no suspension incl). It is super clean, and I'm tempted to whack off my '69 frame at the doors and graft on the super clean later model rear clip. I am capable of this type of operation and have the tools to do the job. My biggest concern is what differences will I encounter between the 2 frames? Is it just the rear cross member/bumper brackets? Would all of the rear suspension attachments be the same? Any clearance issues anyone can point to? I'm not committed to the frame yet, but probably need to make a call either way in the next week or so. Thanks in advance for all the great feedback I know this forum will provide!
chevy69 is offline   Reply With Quote
Old 09-08-2005, 02:02 PM   #2
Nate '69
CF Senior Member
 
Nate '69's Avatar
 
Member Since: Sep 2004
Location: North Texas
Posts: 579
Thanks: 0
Thanked 0 Times in 0 Posts
Default

About the last 24 inches of the 69 frame is different. You would need this section to keep the rear body the same.
Nate '69 is offline   Reply With Quote
Old 09-08-2005, 02:21 PM   #3
chevy69
CF Senior Member
Thread Starter
 
chevy69's Avatar
 
Member Since: Aug 2005
Location: Chandler Arizona
Posts: 3,654
Thanks: 0
Thanked 0 Times in 0 Posts
St. Jude Donor '08
Default

Are the actual frame rails different, or just components that mount to them?
chevy69 is offline   Reply With Quote
Old 09-08-2005, 02:32 PM   #4
Nate '69
CF Senior Member
 
Nate '69's Avatar
 
Member Since: Sep 2004
Location: North Texas
Posts: 579
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Frame rails are different (and components)
Nate '69 is offline   Reply With Quote
Old 09-08-2005, 03:26 PM   #5
chevy69
CF Senior Member
Thread Starter
 
chevy69's Avatar
 
Member Since: Aug 2005
Location: Chandler Arizona
Posts: 3,654
Thanks: 0
Thanked 0 Times in 0 Posts
St. Jude Donor '08
Default

Can anyone comment on what years are the same as my '69 coupe frame? I have heard that 69-73 coupe frames are all identical, provided the same engine/trans configuration is observed. Maybe I should just fix mine, but the idea of starting with something really clean is really eating away at me . I found a guy in CA that has a '69 4spd/SB frame that has been checked, blasted and powder coated for $1900. He says it's rust free, but I'm not sure if he meant before or after the blasting process, and that is a long drive if it's not what I'm looking for. I could go there in a weekend and get it. So far, I can't find anyone in the Phoenix area with a frame for sale. I've heard bare frames usually go for ~ $1000 - $1200 (unrestored). Does this sound reasonable? Thanks again for any/all assistance
chevy69 is offline   Reply With Quote
Old 09-08-2005, 05:34 PM   #6
sb69coupe
CF Senior Member
 
sb69coupe's Avatar
 
Member Since: Mar 1999
Location: Apex NC
Posts: 2,834
Thanks: 0
Thanked 0 Times in 0 Posts
Default

'69 to '72 should be identical. In '73 they went to a different mounting system for the urethane front bumper, which changed the front frame horns. In '73 they also switched to rubber body mounts which were thicker than the aluminum mounts used on '69-'72 cars, so the body mount brackets on the frame are slightly lower on '73 and up frames.
sb69coupe is offline   Reply With Quote
Old 09-08-2005, 05:43 PM   #7
chevy69
CF Senior Member
Thread Starter
 
chevy69's Avatar
 
Member Since: Aug 2005
Location: Chandler Arizona
Posts: 3,654
Thanks: 0
Thanked 0 Times in 0 Posts
St. Jude Donor '08
Default

Thanks, so it sounds as though I'm safe between 69 and 72, giving me four production years worth of cars to pick from. This should help me expand my search. As far as motor mounts, trans cross-members, etc.. is it easy to convert a BB or Automatic frame to a SB/4Spd?
chevy69 is offline   Reply With Quote
Old 09-08-2005, 06:03 PM   #8
not a '76
CF Senior Member
 
Member Since: Aug 2005
Location: Salem MA
Posts: 308
Thanks: 0
Thanked 0 Times in 0 Posts
Default

my car is a 1969 with a 1976 body on it. so the differances are workable between the two years.

edit: but its obviously not a direct fit. and it wouldnt be "original" if thats a big thing with you.

Last edited by not a '76; 09-08-2005 at 06:07 PM.
not a '76 is offline   Reply With Quote
Old 09-08-2005, 06:12 PM   #9
Nate '69
CF Senior Member
 
Nate '69's Avatar
 
Member Since: Sep 2004
Location: North Texas
Posts: 579
Thanks: 0
Thanked 0 Times in 0 Posts
Default

You are good to go with a 69-72 frame. If you want to loose the chrome bumper and change the back half of the body and components then another year could work for you... As far as engine/trans options it doesn't matter much in the scheme of your project. You may need to change the crossmember and such but no big deal.
Nate '69 is offline   Reply With Quote
Old 09-08-2005, 06:22 PM   #10
chevy69
CF Senior Member
Thread Starter
 
chevy69's Avatar
 
Member Since: Aug 2005
Location: Chandler Arizona
Posts: 3,654
Thanks: 0
Thanked 0 Times in 0 Posts
St. Jude Donor '08
Default

I don't think I could live w/o the rear bumper (or the front one either for that matter). Those are a couple of my favorite things about this car. I really appreciate everyone's input, now I can scour the countryside in search of that elusive rust free frame. Can anyone comment on the cost aspect from my earlier post? What should a frame (un-restored) run? What about one that is already blasted and powder coated? I located one in CA for $1900 - is that a reasonable price? Once again thanks for all the advice!!!
chevy69 is offline   Reply With Quote
Old 09-08-2005, 06:43 PM   #11
Nate '69
CF Senior Member
 
Nate '69's Avatar
 
Member Since: Sep 2004
Location: North Texas
Posts: 579
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I think ~$1900 is ok. I'd ask for pictures before and after the treatment and who did the blasting/powdercoating. Of course negotiate if you can..

Maybe you should just work on yours? If you post picks we can comment on the condition. If your frame is that bad you should really check the birdcage too.
Nate '69 is offline   Reply With Quote
Old 09-08-2005, 08:39 PM   #12
chevy69
CF Senior Member
Thread Starter
 
chevy69's Avatar
 
Member Since: Aug 2005
Location: Chandler Arizona
Posts: 3,654
Thanks: 0
Thanked 0 Times in 0 Posts
St. Jude Donor '08
Default

I think I'm ok with the birdcage as far as I can tell. I have a small amount of rust in the windshield frame, but it appears pretty reasonable after closer observation. The doors seem lined up well, and there is no real evidence of decay in areas other that the rear of the frame and the windsheild. I posted something earlier about the rust in my frame and windshield and got good advice from folks on the forum. The frame has a hole in front of the rear drivers wheel (I picked at it with a hammer). It is about 4 inches long and a couple inches wide. The end caps are not rusted through yet and there in no hole on the passenger side in the same location. The trailing arms, pockets, etc... are real scaly, but I haven't found any other rust through and have been over the whole frame including cross members with a hammer and pick. The front is real clean, but the radiator support is bad (bottom). I have not taken the body off yet, but have the car elevated with all the wheels off in my garage on 4 jack stands and have been over it pretty well underneath. I guess the real issue is that I am used to doing street rods, and the frame on my '38 dodge biz coupe is a lot nicer than this '69 vette. I feel confident I can fix it, but wonder if I wouldn't just be happier with a clean start. I can certainly wait to make the call till the body is off. I guess a couple grand would go a long way into fixing my frame. I have a millermatic mig welder and plasma cutter, so I have the right tools to get the job done. The car is numbers matching, but I really want to upgrade my suspension, so I'll likely replace most everything that bolts to the frame. I plan to keep the original 350HP motor and 4spd.
chevy69 is offline   Reply With Quote
Old 09-08-2005, 09:13 PM   #13
GDaina
CF Senior Member
Support Corvetteforum!
 
GDaina's Avatar
 
Member Since: Feb 1999
Location: In Dreams There Is Truth Ohio
Posts: 16,975
Thanks: 0
Thanked 1 Time in 1 Post
Default

You can graft the rear and front horns to the 76 frame, just take good measurements and have a welder.
GDaina is offline   Reply With Quote
Old 09-09-2005, 01:06 AM   #14
dboz
CF Senior Member
 
dboz's Avatar
 
Member Since: Jul 2005
Location: Northeast Ohio
Posts: 866
Thanks: 0
Thanked 1 Time in 1 Post
Default

you can always take the last 6-12 inches of your 69 amd tack onto the rear of the later frame. with some extra plates you can blend the frame differences. I believe the 74 works but you need to drill the holes for the bumpers becasue it won't have them but should still work IMO. I know a guy that has a 74 frame under his 70 and he just drilled for the bumpers. The rear graft should not be difficult with good measurements. I think the front frame horns just need a few extra holes drilled also.

Last edited by dboz; 09-09-2005 at 01:10 AM.
dboz is offline   Reply With Quote
Old 09-09-2005, 08:40 AM   #15
GDaina
CF Senior Member
Support Corvetteforum!
 
GDaina's Avatar
 
Member Since: Feb 1999
Location: In Dreams There Is Truth Ohio
Posts: 16,975
Thanks: 0
Thanked 1 Time in 1 Post
Default

Quote:
Originally Posted by dboz
I know a guy that has a 74 frame under his 70 and he just drilled for the bumpers. The rear graft should not be difficult with good measurements. I think the front frame horns just need a few extra holes drilled also.
did that to a 66..cut off the body mounts and welded the 66 mounts in place
GDaina is offline   Reply With Quote
Old 09-09-2005, 08:38 PM   #16
chevy69
CF Senior Member
Thread Starter
 
chevy69's Avatar
 
Member Since: Aug 2005
Location: Chandler Arizona
Posts: 3,654
Thanks: 0
Thanked 0 Times in 0 Posts
St. Jude Donor '08
Default

Well, I took the day off today and did a lot more poking (and picking) around with my pick. The car probably lost another 5 lbs in rust from the rear sections of the frame. I got rid of the stock mufflers, dropped the spare/holder (still had a red-line glass tire in the well on a rally rim), and removed the rear bumpers, etc... I've had the car a week or two and it's been so hot in the garage I haven't had much of a chance to get after it. I work and hour, then jump in the pool (after a rinse of course). I've decided to run out to Gardena, CA on Sunday and pick up the new frame (12 hrs round trip). For $1900, it will give me a clean start, it's already blasted/checked/powder coated and after 3 conversations with the guy that sells them I'm comfortable. I figure the blasting + work + powder coating is worth that. Besides, since I plan to upgrade my suspension and can probably sell the rolling chassis for enough to make this a no-brainer decision. Any advice on a full suspension kit? Year one has a nice kit for around $2100. Needless to say, my budget is increasing. I figure I'll do whatever it takes. This is the real car of my dreams. It just needs a little help

Last edited by chevy69; 09-09-2005 at 08:51 PM.
chevy69 is offline   Reply With Quote
Go Back   CorvetteForum - Chevrolet Corvette Forum Discussion >
Reload this Page
  • Frame swap on early C3 cars
  •  
     
    Reply

    Related Topics
    Thread Thread Starter Forum Replies Last Post
    67 Project - Update slalomfiend C1 & C2 Corvettes 540 12-22-2017 04:50 PM
    1969 chassis complete rolling frame w/ can am nose steersdad C3 Parts for Sale/Wanted 0 01-10-2017 12:45 PM
    1969 body on a 1980 frame? nellis003 C3 Tech/Performance 11 07-17-2015 11:23 AM
    Recent frame repair and reinforcement pics -- Dialup beware NHvette C3 Tech/Performance 26 10-14-2014 06:17 PM
    Source for Frame-Off Restoration 81vette C3 Tech/Performance 24 01-25-2002 01:53 PM


    Tags
    1968, 69, c3, corvette, fram, frame, interchange, swap

    Thread Tools Search this Thread
    Search this Thread:

    Click for Advanced Search

    Posting Rules
    You may not post new threads
    You may not post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are Off
    Pingbacks are Off
    Refbacks are Off

    Forum Jump

    Sponsored Ads
    Vendor Directory

    All times are GMT -4. The time now is 02:42 AM.


    We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
     
    • Ask a Question
      Get answers from community experts
    Question Title:
    Description:
    Your question will be posted in: