I just got a Trout Unlimited Togiak float tube. It has a couple foam blocks that go in the seat bottom. They only fit in one way, but appear to be about 2 inches longer than the pocket they go into, so I can't get the pocket flap closed. Anyone else have this problem? Am I supposed to need to trim the foam to fit?

I actually read the instructions, which say it is a very tight fit by design, but they don't say anything about needing to trim the foam, nor compress with 400psi. Am I missing something obvious? Hopefully I'm not just being more stupid than a block of foam.

Pete