I typically do a polyurethane paint as well as polyurethane automotive seam sealer to seal off everything after I roll them/cut tabs off.

I also would never roll fenders for a car that you intend to drive on salted roads. It will rust like crazy because you absolutely will damage all the internal coating inside the rear quarter panel, regardless of how good the roll job is.

Don't drive the car the way you have it now.

 

You would need a silly tire size like a 205/40 or something to clear the front.

Either roll the fenders or sell the wheels.