Can I put round gauges in a 64.5?

I actually just did this. I took 66 gauges and put them in a 65 and bought a 65 GT style bezel for them. I had to drill down a little notch in the opening to fit the 66 gauges in, but it wasn't that big of a notch only like 1/4".
 
Here's the gauge support & Autometer version...
I did NOT have to notch the dash. You can simply trim a little off the back of the plastic bezel - it doesn't show when using the Autometer speedo. The gauge support is available thru MDJay, CJPont, and several other places...

http://www.cjponyparts.com/TechGS.asp

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