my friend just built a quad fish and put 4, 3/4 boxes in it. in a thruster or 3 fin, they should all be the same, which if im not mistaken are the 3/4''. the reason he used all 4 the same is so that he can take out the two rear which use side bite fins (which usually have 1/2'' boxes) and move the front to the rear for a really lose twin fin effect without complications. he also had to get these 1/4'' spacers that go under the side bites in the rear so they will fit properly. so again if im not mistaken the smaller fin boxes typically are for longboard sidebites and sometimes quad sidebites. but also the fin boxes on the fins themselves come in both sizes, so depending on which fins you are using or plan to use in the future, you should base your decision in that direction. options, options, options. oh yeah if im wrong someone please tell me.
Last edited by ryanneal83; Nov 27, 2008 at 04:27 AM.
its more commonly done as using 2 side fin boxes as your front fins, and rear fin boxes for the side fins, and/or center. the rears are smaller. running all the same finboxes front and rear so you can run it as a twin seems funky?
Futures makes a lot of side fins with 3/4" bases and center fins with 1/2" bases. Check your JC fins..if the center fin has a smaller fin base, then you need the 1/2" box for the trailer fin. All futures tri fins i've had have been that way.
all thruster fututres fins have the 1/2 center fin and 3/4 sides/ most future quads are 3/4front/1/2 rear, but some have 3/4 rear check the fin; keep in mind the future install kit is 200$ they need to be precisely fit in for they will fail; and greenlightsurfsupply.com is a NJ distributor or all surfboard needs if you want to save some shipping cost.