Yep, do that in a 240, and you might have died.
Good luck on the resolution with the other guy's insurance. They should cover it 100%, but will hassle you on the value of your Supra, especially as they will not have any data for the car's value with the 1JZ motor in there. (You are going to need to supply them with some comparable values both from Ebay, and here would be a good idea.)
Also the cost of the motor, and the cost of the swap would be a good idea to have handy.
They are going to want to keep the salvage, and then will charge you for it.. LOL Get them to come up with as much money as possible, then have them "Waive" the salvage" and let you keep it for free. (This way you get the most money possible from the deal.)
Are you hurt? You should be. Hate to say it, but it will get you more money in the long run, and it will make them handle your property quicker if they think they can resolve your "injury claim" along with the total loss of your car.
If the other guy has no insurance, check his assets, and you can sue in small claims, or use your own insurance if you have collision coverage, and they can subrogate the other guy. (Collect from him, and then you get your deductible back.)
Good luck, and PM me if you have any questions.