Hate to rain on the parade folks but.........
When I was 2 shopping, I came across the nicest 2 I had EVER seen. Absolutely mint, one of kind, with so much tasty and classy things done to it. The guy had sunk in over 7K and was then selling for 1500. I wanted it really bad but wanted a turbo more.
SO...
I called IVI and asked how much it would cost to do a tubby conversion.
NO...
They won't do it.
He told me in no uncertain terms that they will replace an N/A engine in an N/A car and replace a Turbo engine in a turbo car, but no conversions. Too costly in time and expense for them, plus, I got the impression they were busy, doing well, and more interested in quick turnover, easy money projects.
Maybe you could find someone else that will do it, but your history and the cover for this project is with IVI so no dice there.
You could always ask them again, things may have changed, but this was only like 5-6 months ago.