Whups--don't do that!
There should be one barrier strip for the left--and one for the right--amplifier outputs. Each strip should have a clearly marked ground (-) and probably something designating 4 and 8 ohm taps off the output transformer (the + side). I'm not familiar with the taps on the Macs; its possible--unlikely--there is only one barrier strip, but if so, it should designate left and right connections on it like "LG", "L4", "L8", "RG", "R4", and "R8". There is some variation in marking--the ground might be marked "0"; I think it is on my ARC amps. The 4 ohm tap may say +4, or somesuch.
So, the left speaker ground wire (L-) should be connected to the screw on the barrier strip designated as the left side ground (speaker ground will be whatever color of 4TC you connected to the black or (-) speaker post on the left speaker). The other left speaker wire (the other end of the wires connected to the red/white speaker post or + side on the left speaker) should be connected to the screw on the barrier strip designated as either left side 4 ohm or left side 8 ohm, depending upon the nominal impedence of your speaker.
The right speaker will have the ground connected to the right side ground screw, and the other wire connected to the right side 4 ohm or 8 ohm taps.
I don't think using biwire runs of Kimber will be a problem, but it might be hard to get double runs under the barrier strip screws. Because the Kimber is multistranded anyway, you'll have some fun trying to get the screw to come down solidly on the twisted together wires and make a good connection. Because of that, I'd almost suggest using spades. You'll have to get relatively narrow spades to fit between the raised bits on the barrier strip, and get ones with a fairly healthy diameter for the wire end to fit all the Kimber in. Crimp them solidly and it should work pretty well.