you'd do yourself a great service to think of things like this for a long time before you actually post up. most around here don't have patience for half-baked ideas.
rethink your suspension.
the motor is longer and, therefore, will extend further down the body (think transmission tunnel) than a normal motor/trans combo does. also, your structural integrity had better be well thought out or you could end up with the windshield in your lap. that t-bar does a lot more than just give the t-tops a place to rest. i'd hate to think you'd use up all of that gained space with a roll cage, but that would probably be the cheap way out.
pulling the motor and transplanting it are one thing. what transmission would you use? what rear? what rear suspension? will you retain the ferrari's fuel injection? better think about space requirements for essentials, like a computer.
also, if i am not mistaken, the ferrari motor is
wider as well as longer, which will eat into your floorpan on both sides. this is why guys who drive a ferrari for the first time have trouble with the transmission bulge impinging on their normal seated position. they almost claim to have to be a contortionist to drive a ferrari - but that's not true. adjustment is necessary, but it's not that bad.
be careful cutting in the floorpan area, too, as those structural supports do their job. take a look at a third-gen convertible floorpan and see how it differs from a t-top car or even a solid roof car. sub-frame connectors will only be the start of the modifications needed.
i am only touching on certain areas, but you can see it's more than just a little metal work. also, do you plan on doing the work yourself or paying someone to do it? if doing it yourself, i would run your plans by an auto-engineer. if you're paying someone, well, get ready to write several big checks. start out smaller, with something you can easily finish on your own in a coupla weeks. also, let me be the first to tell you that for the same price you can do it yourself, you can buy a crate 383 with a warranty. if you're one of those guys that just has to say he built it himself, well then that's another story.
keep dreaming - it might lead you down the road to that project. just be careful what you throw out into an open public forum.
