Eraserhead wrote:Could something like 5" center and 3.75-4" sides work?
Could. Could not. I think you could probably know everything there is to know about fins and still not really know if it's your ideal setup for a particular board until you ride it. But you've got the right idea. I have a couple of fin sets that are kinda my baseline anytime I get new board, and then I adjust/experiment from there until it feels right. A standard thruster set is a good start.
You could also try running 3.25" sides with something like a 6" Futures compatible center fin, like this: https://www.ebay.com/itm/FCS-Future-Sur ... 3095402885
I don't know about the quality of that particular fin, but I suspect that there are other fin companies that make something similar. You can ask around at your local shop.
You could also talk to the shaper and ask what he recommends as a fin setup for that board based on your size, ability, and the conditions. If you do, I'd be curious to hear back on what he recommends. It's pretty thick, so I bet he shaped it for a big guy who likes to go fast and wants to be sure to make it out of a tube. And since he didn't shape it as 2+1, he probably wouldn't recommend the fin I linked to above, although that doesn't necessarily mean that it won't work for you. That's my guess, anyway. But someone who knows more might tell you differently.