OK,

I spent the day and most of last night pouring over the threads and websites trying to match wheels and tires for my C5.

Here is what I came up with:

Front - Falken 452 275-30-19 - I'm pretty comfy with that.
Sidewall 3.2
Radius 12.7
Width 10.83
Diameter 25.5
Circ 83.8
Revs p/Mile 756

REAR

STOCK
275-40-18
Sidewall 4.33
Radius 13.3
Width 10.83
Diameter 26.66
Circ 83.76
Revs p/Mile 756.45
At 60 MPH I read 60.0MPH (uh, duh!)

NEW - Falken either:

305-25-20
Sidewall 3.0
Radius 13
Width 12.01
Diameter 26
Circ 81.69
Revs p/Mile 775.58
At 60 MPH I read 58.5MPH

285-30-20
Sidewall 3.4
Radius 13.4
Width 11.22
Diameter 26.7
Circ 84
Revs p/Mile 754
At 60 MPH I read 60.2MPH

285-35-19
Sidewall 3.9
Radius 13.4
Width 11.22
Diameter 26.9
Circ 84.4
Revs p/Mile 751
At 60 MPH I read 60.4MPH

So the problem is:

I would really like to have some C5 Z06 style rims, but I can only go with the Motorsports if I go 20, as there is a very limited size availability in 20" wheels.

If I go with the 19" rears, I can probably go with the regular Factory Reproduction wheels.

I like the fact that the 20s have about the same sidewall height (one is .2" up and the other .2" down)

The 285/19s match almost perfect in speed (.2 MPH difference) but have a much higher sidewall difference (.7")

I am concerned that the 305s will stick out. Yes or No? (Falken doesn't make anything in between)

I am concerned that the 285/20s will be too "thin" a sidewall and "roll" into the wheel instead of having a bit of straight-up sidewall like the front. Take a look, the front has more of a vertical (3.1") sidewall then the back. I assume this is a function of width also, but may just be an illusion in the pictures):

http://forums.corvetteforum.com/show....php?t=2056502

I would love some additional input so I can make my final decision. Recommendations on either online dealers or SF Bay Area (or NorCal in general) dealers (or at least reliable places to have my stuff mounted and balanced) would be helpful.

Thanks!

JP