Performance Questions 225 vs. 360

Sully - As an engineer you have to know the desired result must be well settled before any plan is designed. If you're testing the waters here, you'll find folks on both sides of the discussion who are ardent supporters of one or the other...lol
As for me - I've swapped slants for small and big blocks, stick and autos, and been very involved in a GM stovebolt 6 turbo that runs 9s. Which is, once you reach that level, pretty much the same animal as any inline 6.
Some of what I've found:
You do not need more torsion bars or brakes. The differences in weight between a slant 6 and a 440 is about the weight of one passenger; the difference between a slant and a small block is a load of groceries.
You do not need to replace the transmission crossmember. If you use a V8 904, you need no driveshaft.
The cost to swap in a V8 is more - but not much more. You need the running engine. You need the support parts to make it work. You need exhaust work. But to build a slant, you need the same things, but the performance parts cost more. The cam, the manifold, the header, all cost a lot more than V8 stuff new, and are harder to find close by used. (I've tried myself for a year now) Swap meet V8 stuff is all over.
No turbo setup is what I consider "cheap" or "easy".
No supercharger setup is what I consider "cheap" or "easy".

It comes down to what you want. You can have a great running slant and 95% of the public won't care. You can have a terrible running V8 and people will still be interested.
So bearing in mind the desired result - what do you want to do? How much do you have to spend?