Priobe Don't do it. If the car doesn't have to pass a state inspection where the lowest part must be higher that the rims on the wheel, leave it. I have not cut mine and run and raced it for 12 years. I run 17" 335/35 pilot wheels. I have not hit the bell once. My clearance is 4.5" front and rear at the corners of the frame where your behind an in front of the tires. Stance on the car is fine. You are talking 3.0" clearance under the bell housing NJ roads are not the best in the world. Next town over has speed bumps to slow down people in a park area with kids. I have not hit the bottom of the car yet. I do go 5mph over the bumps.
The other question is if there is a failure of the clutch or flywheel, it is easy to bend the block plate without having the bolts and bottom lip to help keep are parts in the bell. I race and drive hard. If you want to trim the botom of the bell leave 1/2" around the bolt holes to bolt the plates together. The minute you trim the bell housing your bell if void of the warranty.
The odds of your clutch or flywheel blowing up are small, but the amount of damage to your car COULD cut the car in half. This I have seen 2 times at the racetrack for 1/4 mile.
If you go to the FE forum and look at the Boss motor that blew up in the dyno cell, this might give you a good idea about the amount of force and damage that a flywheel can do. I have 4 lakewood bellhousing on all my cars and and jeeps. I like walking with my own legs, even if they are old and in poor shape. If you are worried about clearance under the car, than go to a Quicktime bell housing and sell the lakewood. I don't know how bad the roads are in your part of the country, but might are poor.
Rick L.