I'm pretty sure the shock relocation kit from CPP will move your shock out from the rear axle enough to clear with room to spare.
Here is a link.
http://www.ebay.com/itm/1963-64-65-6...item58a0410820
The rear suspension is going to be seriously stiff with those coil over shocks on there.
You need to use a spring compressor on those coil over shocks and the installation will be a lot easier, you can borrow one from o'reilly's and most other auto parts stores that loan tools.