I called about the same thing for my 2015 SP and I was told that it wasnt too hard of a job, and that they could sell just the tank without the filler neck, fuel pickup, etc. I was told to call another guy at the plant to get an exact price, but it was somewhere in the $450-$475 range. That being said, I agree with ClownShoes. For the lakes I fish, I would never need more that the 36 gallons. The only benefit I could see would be resale value. That was almost as much a concern for prospective buyers as the 225 I had on mine.
.
