frame compatibily

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chuckBall
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frame compatibily

Post by chuckBall »

fixing up my grandfather old 1968 2door 429 T have everything off the front end ordered a bunch of parts working my way to the back end. Then noticed a lot of rot on the frame. Does anybody what donor years I can search for to swap out frames body and interior is in great shape. helllpppp please
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Alan H. Tast
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Re: frame compatibily

Post by Alan H. Tast »

First off you'll need to match the wheelbase/body style, as the 4-door Landaus were longer than the 2-door hardtops/Landaus. Second, you'll need to find a good, solid frame - and, quite frankly, frame rot on '67-'71s was their "Achilles' Heel" and pretty much the "kiss of death" back in the day.

I don't know if a '68.5-'71 Lincoln Mk. III frame, which has the longer wheelbase matching the 4-door Landau, would be a candidate for such a swap. Others with previous experience will need to chime in here. Finding a frame dimension chart in Ford/Lincoln service manuals from the period may help to yield an answer to that particular interchange. Here's an example of the T-bird/Mark III frame dimensions from the 1969 Ford Shop Manual, Vol. 4-Body: note that dimensions for the Mark III are different from the T-bird in the front for the front clip mounting point, and that the rear third of the frame has two sets of dimensions (numbers in circles are in inches) starting just forward of the frame kick-up: the upper datum numbers are for the 2-door 'Bird, the bottom ones are for the 4-door 'Bird/Mark III. the rear third of the frame is 2.5" longer for the Mark III/T-bird 4-door Landau.
69 T-bird/Mk III Frame (from 1969 Shop Manual Vol. 4-Body)
69 T-bird/Mk III Frame (from 1969 Shop Manual Vol. 4-Body)
Can an existing frame be rebuilt/repaired that's rotted out? Anything's possible given the right equipment, proper materials (thickness and type of metal), sufficient amount of funds, etc. As I've never personally studied the box construction of a '67-'71 frame in depth I can't say if repair is possible, but it would require being able to have a sufficient amount of material to weld to and maintain structural integrity.

Please provide photos of your frame and where it's rotted out so that others can chime in on whether this is repairable or if it's a lost cause.
Last edited by Alan H. Tast on Fri Jan 15, 2021 10:57 am, edited 1 time in total.
Alan H. Tast, AIA
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chuckBall
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Re: frame compatibily

Post by chuckBall »

Kijiji Montreal 1968 ford thunderbird for sale is where I posted the pictures of the frame seems to be the box part of the frame in the middle section is is possible to replace this section without having to lift the body. Does anybody know what vehicles could be donor frames it would be a shame to have to scrape it.
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Alan H. Tast
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Re: frame compatibily

Post by Alan H. Tast »

If you're dealing with a 2-door, there probably isn't another platform or frame to swap with - the T-bird only shared frames with a Mark III, and that's only if the T-bird is a 4-door.

You would need to take the body off the frame to properly repair it as you'd need to have a full penetration weld around the entire box section.

Now maybe you can understand why there's so few 67-71s out there.
Alan H. Tast, AIA
Technical Director/Past President,
Vintage Thunderbird Club Int'l.
Author, "Thunderbird 1955-1966" & "Thunderbird 50 Years"
1963 Hardtop & 1963 Sports Roadster
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Alan H. Tast
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Re: frame compatibily

Post by Alan H. Tast »

For future reference, I copied the pictures from your 'for sale' posting. It's hard to tell but it looks like the rustout that's pictured is between the driver's front wheel at the front body mount, and continues rearward under the doors. That's a classic example of how Ford-made frames of the period went bad.
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What is the condition of the frame near the rear kick-up? At the top of the kick-up over the rear axle?

You might want to take a look at what some comments are about repairing full-size Ford frames from this period here: it looks like the full-size '75-'68 Fords had a similar problem, with rot-out of the frame under the doors and at the rear frame kick-up. You may want to get to know someone at a sheet metal or metal fabrication shop who can bend heavier-gauge metal, and learn how to weld - collision shops won't touch an old car like this to repair the frame. Or, plan on trying to find a frame somewhere in the southwest USofA (good luck with that).

https://www.fordmuscleforums.com/thread ... ce.441543/
Alan H. Tast, AIA
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Vintage Thunderbird Club Int'l.
Author, "Thunderbird 1955-1966" & "Thunderbird 50 Years"
1963 Hardtop & 1963 Sports Roadster
Phosgood
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Re: frame compatibily

Post by Phosgood »

If several inches were cut out of the MkIII frame between the "10" and "60" points. would the 2
dr body not fit?
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Alan H. Tast
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Re: frame compatibily

Post by Alan H. Tast »

Several? The difference between the two frames/body styles from just forward of the kick-up where the body mount is 2-1/2-inches. However, there are other difference in the front of the frame where the front fenders/radiator core support mounts. Either way, slicing and dicing a frame is going to require something more substantial than squirting a weld with a MIG from Harbor Freight.
Alan H. Tast, AIA
Technical Director/Past President,
Vintage Thunderbird Club Int'l.
Author, "Thunderbird 1955-1966" & "Thunderbird 50 Years"
1963 Hardtop & 1963 Sports Roadster
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