shrinking 6x6 T3s

I need to get some lr T3s down to 31 3/4-32", they are on 8.75" wheeels but I can't get them smaller than 32 3/8. Using 10-12 minutes at 300 degrees and ice water. Any sugggestions? I know I can stretch the rr to get the desired result but I would rather get the lr down. John