MSD wiring

I have an MSD ready to run billet distributer. My vehicle is a 65 Chevelle with a 327, 350 trans. I have done some research here but still have a few questions on wiring this distributer. There are 3 wires on the distributor , black, red, and orange. The black one goes to the ground, red goes to the positive side of the coil, and the orange to the negative side . My question is, What wire do I use to hook up to the positive side that goes to the ignition switch ?? I have read here that I cannot use the cloth covered wire that comes from the fuse box( I have the original fuse box). I have also read that I can use a whole separate wire from the IGN spade terminal on the fuse box to the coil. If so , what gauge should I use ? My fuse box has 2 spade terminals labeled IGN. I am already using one for my electric choke. Is it ok if I use the second one for the distributor. ??? Thanks in advance.

I am reading that red goes to positive on coil, from that positive coil goes to a key ignition

orange goes to negative on coil

black goes to ground,

I got this info from the link given, it is a part # 8360 distributor.

also the wire guage should be the same as, or a size bigger, never smaller. as far as running the 2nd teminal labled ign. for the distributor, without seeing it I cant say, but if its 12 volt I would try that if it were my car.

http://www.msdignition.com/pdf/8360_frm%2023793.pdf