wheels/tires

["Hall, Phillip" <Phillip.Hall@msfc.nasa.gov>]

List-

What is the largest 15" wheel and tire that will fit under a Roadster, and
the offset of the Roadster wheel.  I have rolled Roadster fenders in the
past with good luck using 14" tires/wheels and can do it again on my '66.
Also, is the offset the same as most Z cars?
And - can I run comp. front springs with 15" wheels?

Thanks 
Phil Hall
'66 1600