Rather than make my last post massive, I decided to make option 3 as it's own post. This one is a partial redesign as well, so it will take some work. If this seems like too much to handle, don't attempt it. With that being said, here we go.
Step 1. Trace around ALL the framing parts using 1/16th ply instead of 1/8 except the sponson sheers, they need to be 1/8. Be sure to lengthen the tabs like in option 2. One change you can make is to widen the engine bay to 4" if it's not that wide from the factory. I can explain that proceedure if needed later. Mark but do not cut any of the interlocking slots on any parts for now. Cut out all the parts and set asside all but the furthest forward frame, radio box front, transom and one sponson inside
Step 2. Cut the slots for the furthest forward frame and the front of the radio box in the sponson inside and the interlocking slot in this part of the frame only. Be sure the slots are big enough for the frames to fit without being tight. Excess space isn't good.
Step 3. Slip the two frames and transom into the slots cut in the sponson inside and, using a straigh edge, draw a line from the bottom of the transom to the radio box front and then to the front frame. This gives you the modified bottom profile. Glue a 1/8" piece of square spruce along the top of this line. Now repeat the process on the other sponson inside, making sure there is a left and a right
Step 4. Cut out the remaining slots, again making sure they are not sloppy or tight in fit. You will need to modify the frame between the front frame and radio box front as the bottom will be higher in this area than in the stock kit. You will also need to notch the frames to clear the previously installed glue blocks. Dry assemble the framework and mark the engine bay walls so they match the new bottom profile, remove the excess and install glue blocks along the bottom edge again making sure there is a left and a right. Reinstall the engine bay walls with the glue blocks facing the sponson insides
Step 5. Install the bottom as described in the kit instructions. You may need to use new material if the boat was widened or the supplied parts no longer will work.
Step 6. Cut lightening holes out of all the underdeck framing. This will lighten up the hull and make draining any water that may get in possible. When you're finished, the boat will look like this, except without the sides and sponsons skinned. In the case of my boat, I made several changes, such as moving the fuel tank under the deck with a bottom access hatch and running the cooling lines under the deck, but all that will come later. If this looks like something you want to try I can go further later
