I've been following the saga of the MX5 V6 by Rocketeer...
Take a 20 year old MX5, take out the cast iron 1,8 L four and replace with an all alloy Jaguar 3.0L V6. Same weight, the MX5 box matches and yours for £15,000 to £20,000
Piston Heads love it....https://www.youtube.com/watch?v=Ayo5EJS96S8&t=10s
If I had to sell the Porsche I'd be tempted.