changing out old 27 hp with 32 hp.. do i need to get a new prop? prop has 486 hrs.

You may. The newer two blade they use is for the 32 or 27. The new 3 blade that comes with the 27 will work on the 32. But they used to be different. I prefered the older 32 prop on my 27, and my dad preferred the older 27 prop on his 32. Just run it, if you think you need to change it, then change it. He was riding close to the gov with the smaller prop on the 32, but it jumped out of the hole, and carried a load well.