I missed the "giant" part, sorry.

Weight is only one issue, how about all that drag. GEEEEZ.

Dude, you need more motor.

It may get off the ground, however I got money says it don't come back to the ground in the same condition.

Do you have a 91 on it now because it is the only thing you have? Cannot afford another motor? Or you just wanna try it? Almost any reason you give will not help the fait of your bird.

Don't do it.

However if you try it, hope you have a long paved runway and make sure to get vid of it. Can't wait to see that stall on the first turn downwind.