NO-didn't do anything more then bolt them on , really . There is 5" of clearance from the top of the 15" tires to the wheel well and 2- 1/2 " side clearance .
The tires are Carlisle ST 205/75/15R
got the wheels from Vintage Trailer Supply ( 15 " x 6" 5 on 4-1/2 bolt pattern )
I've never liked aluminum wheels and those 13" wheels/tires made the trailer look like a fat man on ice skates .
This is a picture from underneath - Looking up at the inner wheel well side clearance .
I put a long piece of Duck Tape on the inside of each wheel well to see if there was any rubbing and after 800 plus miles so far the tape is still intact .
Be careful and take a lot of measurements , It worked for me ......