I go to the hardware store and get heavy duty blind nuts. The type that has 6 tangs is the stoutest but there's some good ones with 4 tangs.
After you get your holes and nuts and dowels all lined up tighter them down on the firewall to set the blind nuts. Get them good and tight. Then release them and mount everything back up with the motor. Just before tightening the bolts drip some CA on the dowels and quickly tighten every thing. Make sure they are close to the same length first or you will warp the motor mounting lugs.
One other thing, remove the engine again and sand the ends of the dowels flat after tightening and setting the glue. I use a hand size hard board and sandpaper. You want all four to touch evanly.
I don't know what you need the CF plate for. If anything else, some angle stock, one at each corner of the dowels to keep them from moving would be good but I don't do that with my dowel mounts, just the dowels.
Check for tightnes after a few flights and then again every 10 or so till you are sure they are done seating.