Will an eave mount support work for this setup ?
 

If I use a Channel Master CM 9030 Adjustable Eave Mount that is securely mounted and use a 1.250 sectional mast , how high can I safely go above the mount ? Would like to use 2 antennas , a Antennacraft HD1200 VHF\UHF that I currently have and add a 91XG on top of it. Will I be able to do this without guywire supports. I believe I would need a min. 4 foot spacing between antennas.

Thanks

I'm using a similar bracket type, supporting a 10' section of mast. There is 7 to 8' of un-guyed mast above the top bracket. With a CM3016 antenna at the top, I get some wobble in high winds, I would not put a larger antenna up there without guys. I would recommend guying each section of a multi-section tubular mast.

Both of the antennas you are using are quite a bit larger than the CM3016 (and more expensive). I would be far more comfortable guying the mast that has to carry all that wind load.