HI
The Fins from my Liquid Force proof 151 (love this board) are cheap plastic & the thread has come loose so need replacements however the screw thread is unusually narrow ( my older proof board had standard wider gauge screws that we're pretty universal)
Anyway does anyone know any decent fins with narrow threads to suit?

You 4mm threads instead of 5mm?

Hey man, just a option: is it possible to redrill your board to 6mm and have access to all the normal m6 fins? I did this with a ten year old LF board (basically a wake board) and it worked no wakkas (the core was rubber foam)

Yep plummet 4mm or possibly 3.5mm
Yess AC there is a possibility I could drill out wider but not entirely sure. This board did not cost a fortune but I searched everywhere to get it as I have the same board previously and no other board comes close IMO :)