Prelucar said..
I’ve also seen posts on this forum saying that putting a larger fin on a freestyle board isn’t a good idea.
Only as it kills the freestyle ability. For blasting the bigger fin is exactly what you want as freestyle boards are deliberately very underfinned to get them to slide, and fin to not catch the water in spinny jumps. Their flat rocker is just like a freeride board.
A FSW has nothing to do with freestyle really, its a fast rockered waveboard or a detuned freeride with more tail rocker so it turns OK on waves.
I'm basing this partly on you using an old freestyle board - some modern freestyles are so specialised that whilst they plane up really fast they don't have the vee up front to handle fast over chop = as they are just get up quick then bust out a move. Not designed for comfort fast over chop for obvious reasons.
I guarantee that board will feel great with something like a MFC freewave or liquid pro, 30-34cm ish, and that 6.6.
