Ironcross, the Magnum 1.20FS, being a shameless copy of the OS 1.20FS, weighs very close to it. 31.5 Oz or something like that. IIRC, the Saito 1.20 is actually a tad heavier, not much.

The Saito 1.00 beats all three 1.20FS on power-to-weigh ratio, hands down, and probably a better bet for your 66" Extra. Don't know which one you are refering to, but it sounds like a .60-.90 size bird. If so, the Magnum is not such a bad choice either, especially if it need nose weight anyway. It's not really a fair comparison. It only make sense because their street price will end up being about the same. The Saito 1.00 might pull close to the same max RPM on some props, but the 1.20FS will still has a fatter powerband and, therefore, better all around tractable power, IMHO. The extra bit of cu. in. aren't just there for the ride, you know.

I would get the plane first before deciding. If it seems like it should balance fine with the Saito 1.00, I'd go with that. Lighter still flies better.