I have a triumph spitfire in our garage and I was curious of whether a sr20 swap would be possible. And if it was would it be worth the work for the swap?  

It would certainly be original. Whether it would be worth the work...? That's a question only you can answer. What is the value of the car to you, personally? And in the end, it is you that's going to be in it more than any one else.
Any thing is possible as long as you desire it and have the time and money to do it. I wouldn't knock you for doing it. I think it wuld be cool to see.