911SCRVA,
You're getting good advice from experienced DIYers and recognized pros. Some questions:
- what is the problem with the engine? Is it a running, but tired, high mileage original with bad leakdown and compression or is it damaged (over-rev, neglect, unknown history)
- what are your goals? a good running stock motor? a hot-rod?
- what kind of budget do you have? would you opt for new Mahle piston and cylinders or would you economize with replated cylinders and aftermarket pistons?
I agree a DIY rebuild is feasible and lots of us have done it. You need good resources (factory manual, Wayne's rebuild book, this forum), some mechanical aptitude, patience, determination, a good attitude and (as Neil says) a plan.
One challenge for inexperienced builder (like me), is knowing what is re-usable and what has to be replaced. Sometimes it is a matter of measurements, but other times it takes a practiced eye (when I did my first transmission rebuild having a pro look at the disassembled unit and identify what needed replacement was invaluable).
Given all that, you are not too far from Bruce (Flat6pac). You might want to talk to him about options.
Good luck.