Gents,

I've got a '87 C4 convertible, and a '85 targa.

Say I would want the chassis from the '85 under the '87 .... (so, everything '87 except for the chassis itself)

what would I be looking at? Has anyone done it before? I've googled all morning, but can't find any occurences...
How hard is it, what are the pitfalls, is the chassis any different '85 to '87 and targa to convertible, ... )

(I come from a background of wrenching on Land Rovers, where a chassis swap is all of a weekend's work )

Thanks a lot for your help guys!

Quentin

 

I'm pretty sure 85-87 are the same less one of the cars have the Z51 rpo. All you would be doing is swapping worn paets for less worn parts. You mentioned one of them being a vert. Keep the x brace. Save your self the trouble and go to a good service station and have them do a good once over on the underside of the cars and replace what's needed first and then hit up VB&P for a polly bushing kit. Do eather of the cars have the Z51 rpo? That car has the springs you want and better shocks but no sence in replacinf old shocks with older shocks

 

Hi Hamrhed42,

thanks for your reply, but I believe you're missing the point. That's understandable, since I didn't quite explain it well.

Let's say in the country I live there's a good reason to drive a '85 rather than a '87. However, the '87 is in better shape, and is a vert which is nice.

So, just take my word for it, I have plenty reason (none of which technical, yet valid nonetheless) to switch chassis'. IF, that is, it's doable.

Look at it this way:

-'85 targa: everything bad, broken, burnt, worn except the chassis
-'87 vert: chassis bad, broken, burnt, magically disintegrated, all the rest is A+ good perfect.

=> how stupidly much work is it ;-) ?

cheers,
Quentin

 

Ok I see a little bit better now. Probly with a few friends and a case of beer and a plan I would say a weekend of solid work would get you done those 2 years are more or less swappable part for part. 87 was the first year to have standard ABS brakes and it had a roller block so good choice (or lucky) on the upgrade. Are they both the same tranny? The auto had a dana 36 and the standard had a dana 44.

 

'87 is an auto, another reason why I want that one ;-)

Thanks for your reply! The differences you sum up confirm the plan to make the 87 an 85 is better than to strip the 87 for the few parts the 85 is missing (such as the engine), as ABS and a Dana 44 are quite nice to have indeed ;-)

Although, the more I think of it, it really would be A LOT easier to just angle-grind the VIN's and re-tag it, too bad that's so ****ing illegal

Swapping chassis' I'm just doing sooooo much work basically for an administrative little glitch ... I hate living here!

Greetz
Quentin

 

What exactly is the big difference in the two year gap administratively? Some antique classification? Did your DMV screw up the paperwork somehow?

 

Spot on, both.

To give you an idea, in my country taxes are about €2300 yearly to drive the 87, and about €50 for the '85. Now, I could wait 2 years to drive the '87, i've no problem with that, were it not that our local DMV permanently screwed the paperwork on that one ...

The '85 however has had an engine fire so it's not exactly driveable ...

I just want a weekend cruising 'Vette so badly, and the '87 right now is only good for parts, which is just a shame!! I'd love to bring it back to her full glory!

Look at her, just needs some TLC ... :wink:

 

It took me a weekend to completely pull the 92 suspension off, did not include the batwing and diff.
I've seen posts from folks swapping engines taking the same time.

Guessing 7 days if you can stay at it.

Good luck sticking it to the man!

 

Wow.

OK, good info, thanks mate!

Definitely different ballpark from the Landies I normally wrench on.

guess I'll have to find some other way to do it then .... this is just not realistic.

 

The C4 chassis is not like the C3 Corvettes where the car is built on a body on frame configuration. Some of the body parts on the C4 are bonded onto the chassis and cannot be bolted and removed. It would probably make sense to switch over the running gear and suspension from the 2 cars if I understand correctly what you are trying to do.

 

Quite useful information and definitely the killing blow to my chassis-swapping plans.

Ok, other options ...

-go illegal; wouldn't want to do that now would we (swap VIN's)
-strip the '87 for parts (noooooooo! poor 'Vette!)
-rebuild the '85 ... not financially nor practically viable.

so ... where are the VIN's located on these Vette's ?

 

Look through the bottom of the windshield on the driver's side. If you remove the windshield, you might have someone cut out this section and graft it onto the other car. You didn't hear this from me.

 

And I'm absolutely not going to do something like this.

Thx everyone for your help!

i'll come back around when I've some experience wrenching on it and will perhaps be able to give something back to the community in form of tech advice or anything ;-)

cheers,
Quentin

 

There is a vin # on the sticker, drivers door.

Also a build sheet on top of the gas tank.

There may be a second build sheet in the front crossmember.

 

anything stamped in the chassis?

 

There is also part of the VIN stamped on the frame rail in front of the battery. IIRC it's the last 12 numbers. I have also heard that the complete VIN is stamped on the inside of the frame at the passenger side frame kickup.

The C4 body is attached through an adhesive and not a bolt-on process like most other cars.

If the 87 has been through a fire, it couild be that there was enough heat around the forward portion of the frame rails that they could have become weak. It's possible to cut the front part of the frame off of the 87 and weld the same piece from the 85 in place. Lots of work and you will need a way to insure that everything lines up properly. A frame straightener that would be found at larger collision repair shop is what you would want along with a really experienced welder to do the cutting and welding.

There is little if any difference in the dimensions of the suspension components between the two cars but the 85 will have a stiffer spring especially if that car had the Z51 performance suspension. Z51 was not available on convertibles. Shocks, springs, control arms, brakes are all interchangeable.

The rear suspension is a bolt on along with the components, but you would need to retain the hubs and knuckles to keep the ABS. Each wheel has a speed sensor that attaches in the knuckle.

Moving ABS to the 85 is really not a doable option. You would need all of the brake lines and the ABS pump from the 87. Then you would have to fabricate a mounting for it.

If the 87 is toast, you may be better off by building the 85. The 87 motor is a drop-in and will have the benefit of aluminum heads and slightly more HP and torque.

 

Allright, think I've enough to work out my plan ...

I'll drop off some pictures here when it's all done ;-)

thanks again guys, really helpful forum, not often the case when a newbie comes around asking stupid questions - hope I'll be able to return the favor sometime.

Cheers,
Quentin