I went out and measured mine for you by taking a 8' level and laying it across the canopy then measuring from the floor in the barn up I parked the tractor on a couple pieces of 1" plywood and it was pretty level about 3/4s of a bubble off
I came up with 99 on one side and just a little over 98 on the other measured close to the floorboards.
This tractor has R4 tires that are loaded and cast wheel weights on it plus a backhoe hanging off the back the back height with it in the running position was 97 3/4".
An 8' opening isn't going to cut it you'll probably want to go with a 9' opening.