70 boby to 74 frame swap

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Apr 9, 2015 | 05:49 PM

ALPINEMETAL

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From: Alpine Socialist Republik of Kalifornia

70 boby to 74 frame swap

My 70 coupe was originally a Minnesota car and the frame isn't in the best of shape. It's originally a 350/350 4sp manual steering and brakes, non tilt wheel. I picked up a California 74 donor without engine trans or much interior but it had power steering, power brakes and the tilt wheel I need, as I got to looking at it the frame looks almost new and was probably repainted or powder coated. I'm not sure if it was originally an automatic but dang the frame is perfect. My question is; is the only issues the lower rear section body mount (I can shim right?), and drilling for the rear bumper?

Is this a good swap?

Thanks for your help.

Apr 11, 2015 | 12:34 PM

Easy Mike

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From: Southbound

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http://www.71corvette.com/frames.html

Keep in mind the 74 frame was designed for crash bumpers.

AT frames have bolt in cross members. The cross members are welded in for standard tranny cars.

Apr 11, 2015 | 01:52 PM

ALPINEMETAL

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From: Alpine Socialist Republik of Kalifornia

Yes the 74 bumper system bolt to the frame but the holes line if with the holes on the 70. Do if desired a 70 frame could be used on the 74 and I think up to a 77 ( I'll defer as I'm still learning vettes ( gen 1 and Gen 2 camaro's I'm all over)

Apr 11, 2015 | 02:26 PM

Alan 71

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From: Westminster Maryland

Hi A,
"Is this a good swap?"
It seems to be a swap of 'convenience' at this point.
I think it depends on what the rest of the car will be as to whether it's a "good swap" or not.
Some 70s would certainly be devalued by using a 74 frame. The further your car is from 'original' the less impact the 74 frame will have.
So it could matter not at all, or it could matter a whole lot.
Regards,
Alan

Last edited by Alan 71; Apr 11, 2015 at 05:13 PM.

Apr 11, 2015 | 03:12 PM

ALPINEMETAL

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From: Alpine Socialist Republik of Kalifornia

The original engine was replaced with a C coded (crate) engine from the factory probably sometime after 74. The frame is pretty rusty being from originally from The land of 10,000 lakes rain snow sleet and salty roads. The 74 frame I have is mint possibly powder coated. without the original motor the collector value was lost long ago. Besides I want ps PB and tilt, nothing that was originally on my 70. I'm building myself a fun driver, I've already picked up a set of performer heads wth rollers. B

Apr 11, 2015 | 05:12 PM

Alan 71

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From: Westminster Maryland

Hi A,
Then it sounds like you're on the right track!
Regards,
Alan

Apr 12, 2015 | 04:24 AM

tfi racing

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From: Cedar,BC

Nothing to it,a bit of work with a cut-off blade then flap-disk in your angle grinder,then rework a couple of holes for the rear bumper brackets,the toughest part should be matching the paint or powder coat on your new frame.

Apr 12, 2015 | 07:28 PM

70LQ4

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From: Warsaw Ohio

Frames are the same up to and including 74. The only difference is the rear Bumper bolt holes and the Welded Nuts for the front Bumper braces. Also You will need to shim the body mounts to make up for the difference the frame mounts were lowered for the 73-up rubber mounts. Done this several times, 74 Frames are much cheaper than 69-72.

Stan.