1968 engine upgrade
 

Hi, this is my first posts on here, recently inherited (mid last year) my uncles 1968 porsche 911 s with a SKT Mega III kit on it, pearl black, you can just sit there admiring it all day before you realise it actually drives, then driving it home after work, just cruising along on the freeway, not a worry in the world, then you see some guy next to you in his riced out integra trying to get you to go him, you dont pay him any respect, he wouldnt have the capacity to realise just what the 911 is, the history, the passion, the feeling that every owner got when they first drove it, and still gets.

Now to my question, my engine is 170+k's and having troubles with it, and now i am thinking about swapping the engine out, want to stay with the porsche engines, just wondering if it can be done and what model engines it can be done with, if possible also how much it would cost and what needs to be upgraded besides from the newer engine that would be going in, with the engine doesnt matter which one, not looking at water cooled ones, any air cooled one basically from 1972 onwards, sure the newer it could be would be good but 72 onwards will do.

Thanks to anyone that can reply with any help