Thanks.  Unfortunately, even Internet 'experts' are confusing.  One said the offset is in reference to "the street side" of the wheel.  Isn't the Street Side down? 

Tom,  This website should help you understand.  Play with the offsets and watch the graphic.

 

http://www.rimsntires.com/specspro.jsp

Do you happen to know the offset of the ZX 6-spoke rims?

No, but I'd guess between zero and +6mm.

It's a place to start...

A quick internet search didn't help.  I found people claiming everything from zero to +12mm for the six spoke wheels.  I would trust the zero claim the most since the site listed the offsets and weights for many of the common stock and aftermarket Z wheels.

cant speak for the zx, but fwiw these came off my 74 and have a 4 inch backspace.

 

Edited July 26, 20159 yr by awconroy

Why would you need "hub extenders" to install the ZX wheels?

You don't need  hub extenders to attach the ZX wheels, but you do need to know how much room you have to work with for different wheels, considering the offset and backspacing of the ZX wheels.

You talk about changing between bolt paterns, and spacing what wheels are you looking at?  You might want to look at changing the hubs.  This might not be a bad idea. 

 

On my first Z I looked into several rims and the cost of custom rims were minimal when you add in the spacer cost.  SO I went with Colorado Custom rims.  It was worth it because the wheels fit perfect. 

I recently became aware of some wheel hub extenders/adapters  that will convert the 4-bolt hubs to 5-bolt hubs.  They are basically two disks;  the first one has 4 holes and bolts to the original hub, and the second disk has the 5 new studs on it.