It would be expensive to build and would require a decent amount of mechanical knowledge. You can buy a kit or kit car from Caterham to build the complete car or they will build it for you and sell it to you.
You are looking at close to 20k to have a complete running car with out paint if I am correct(could be wrong lol).
Why would you want to put the 5.0 in one? The 5.0 would greatly offset the suspension and make the front end incredibly heavy. The handling of the car would be thrown off quite a bit with that heavy of an engine in it. Why not one of the Cosworth engines that Caterham uses? The Cosworth engines are light, make awesome power, and are very reliable.
With the 4 cylinders in the cars the car weighs between 500 and 600kg without the driver. That makes even the low powered ones incredibly fast. The high powered ones are too fast more most average driver's and they still only come with 260hp, but go 0-60 in 3 seconds or less and top out over 150mph. That is quite fast in an open top car.
Go to
Caterham Cars - Designed for racing, built for living to get more info and see how expensive it is going to be. It would definitely be a nice car to have if you were rich and loved to road race.
caterham lotus super seven 
