Tens were as big as I could get while still keeping the full size spare between the boxes. I have templates for the side panels which are the hardest to make. The false wall would have to be figured out on your own. I can give ya the rough dimensions to start with on it but it will require a lot of sanding and test fitting to get a good tight fit.
I'm from Las Vegas and was with the SSincitySS chapter. I had to move to Iowa for a job. Vegas's economy was ruff. kept getting layed off. But I hope to return once the economy is better. I'm interested in meeting others in the area that are B-Body enthusiasts.