84 Corvette to C6 Wheels....
 

Hi...

I just picked up a set of the rare optional Magnesium C5/C6 Wheels!! I have looked all over (google) to determine what I need to put these on my 84 Corvette?

I have not physically tried to install them yet. Most of what I have read says that I will need some sort of "spacer" for both front and rear?

Where do I purchase these?

How thick of a spacer do I need?

Do they need to be "hubcentric"?

I hope to have a running car by the first weekend in August as long as the fuel pump replacement goes well... If so, then replace the AC Compressor and charge it and hopefully good to go...

Then Ill remove the Instrument Cluster and send it off to be repaired.

The wheel conversion will be the last step, but Id rather get whatever I need coming....

Thanks again, I appreciate all the help!!

Steve

:southpark:

Anyone checking in here have any clues?

Try search...

Try CF.....

I'd get in touch with a tire or rim dealer, and see what they think.

:iagree:

You might have an issue with offset, the depth within the wheel well....

There was no magnesium wheel option for the C6, so you have C5 wheels.

The optional C5 magnesium wheels look like this:
Attachment 4777

Now, doing the offset math...

The 1984 wheels appear to be either 16x8.5"-32mm offset, or with Z51 pkg, 16x9.5"-38mm offset on the rear.

If the calculated dimensions below seem confusing, keep in mind a wheel's stated width is 1" less than actual. Stated width is measured where where tire bead seats, and does not include the lips. But, backspace and frontspace dimensions does include the lip thickness, which is 1/2" inside and out.

The C4 wheel specs work out to this:
16x8.5"-32mm = 6.01" backspace, 3.49" frontspace
16x9.5"-38mm = 6.75" backspace, 3.75" frontspace

The C5 wheels are:
17x8.5"-58mm = 7.03" backspace. 2.47" frontspace
18x9.5"-65mm = 7.81" backspace, 2.69" frontspace

So yes, those C5 wheels will be tucked in about 1" more than the stock`84 wheels. If the additional backspace doesn't present a suspension clearance issue (I don't know), they may bolt on and work as-is...But if you want them pushed out to fit closer with the fender edge (to fit about the same as the stock wheels), you will want a 1" thick (or 25mm) spacer.

With spacers that thick, they will come with their own studs, and have holes and thin nuts to attach it to the stock studs. You might have to trim the stock lug studs to do this, or replace them with shorter ones, but I believe 1" are thick enough to avoid that problem.
And yes you want them to be hubcentric, and for that, you need to know the centerbore size, which is 70.3mm.

Here's an example link of what you're looking for (note these are generally sold in pairs, you will want them all around, so 2 pairs):
2 1" inch Hubcentric 5x4 75 Wheel Spacers Adapters 70 5mm Chevy GMC Pontiac | eBay

I'm making no claim of the quality of those, they are very cheap, and personally, this is not a part I'd go cheap on. If you want top quality spacers, look at H&R, but you'll find them to be quite expensive in comparison, $250-300 for a set of 4. I think H&R part#5085704 are the ones that will fit this application.

Hope that helps
:cheers:

Wow! Ain't it nice we have other eyes checking in!!!!

Always appreciated!

:hurray:

WOW.... Thanks so much for setting me straight!! Those are the exact wheels I have!!

Thanks again,

Steve

If/when you get these on the car, please attach some pics. I imagine those wheels will look pretty good on a C4. :seasix:

Will do..

Thanks again for your help!!

I'm ordering spacers next week, once I get home!!

Steve

I have the chrome wagon wheel C5's on my '85. Previous owner installed them.
They clear fine but do tuck in a little. I am looking to get spacers as well or get C4 wheels.

Attachment 17433

Attachment 17434

Attachment 17435