I had to run worn out 31's with my 4 inch lift for awhile because I put off getting new rubber. Didn't look that bad, but I must say it looks MUCH better with 33's. I don't think your highway hill problem would be solved or even partially rectified with a tire change to 32's.
Tell us a little about your motor and it's set up. You may be able to keep the 33's if you pep up your motor. If you have the stock motor, you might consider getting yourself a header and better exhaust. Do you have an HEI ignition? If not then that would get you a couple more ponies. Do some small mods to get you more power and you should be able to swing the 33's no problems.
Design311, i posted something along with this about my engine and getting my cruiser to at least keep a good 65 n the highway. read that it should help. i have the stcok dist and a weber, new fuel filters and fuel pump. it does need a vlave job though