Awesome stuff Simon.. Will be good to see some useful information moved out somewhere else ..
Anyway, I wasn't going to end up posting this as a lot of it was just another blow up @ Sublime, but I've edited out all but the important stuff .. so here goes my attempt to address some of the issues brought up throughout the thread..
I never said that the 6a13 conversion has less risk of problems arising, if anything there is more risk .. (just not from the engine blowing up)
It isn't in dispute that the 6a13 engine is "made for a turbo & that the
engine is going to hold up to high boost better than the 6a12"
Is it easier to do an engine conversion
Short answer: No, it's not necessarily going to be easier
But, honestly, does anyone really care if it's easier?
Most people aren't going to be doing it themselves anyway, and those that are going to do the majority of it themselves aren't really going to care, it's all part of the fun..
The real question should be "How much will it cost to get a workshop to do the whole thing?" & "How much will it cost to get a workshop to do all the hard stuff?"
Is there less chance of having problems?"
Put it this way, you're running three times as much power through the rest of the components that weren't designed for it.. the engine is pretty tough & the bottom end has some strengthening as stock & without forged internals it's good for at least 16 PSI (possibly 18- Low 20's)
At least with a turbo 6a12 running 5-7 PSI of boost, the load you're putting on the other parts is not nearly as significant.. and the engine should hold up to it, provided that you have a good tune..
If you've read Sam's thread/s they are a good example of what could go wrong, but really it doesn't mean sh*t .. he was / is going for insanely high HP on a highly modified, unproven engine .. even before that, he was pushing the limits of the 6a12 engine & some unfortunate events led to it giving out... but I don't think it's typical of most turbo conversions out there.. Look at all the other threads on turbo conversions .. there are dozens of successful turbo projects on these forums / FTOOC that didn't encounter nearly as many issues as Sams, or Jeff's & Danny's .. not to mention FTOEvolution is just now starting to notice his diff dying..
Even Ben & Mitch have come across quite a few problems doing their conversions, granted, it's not 'hard' to hand over money to a professional to get custom fabrication, or other difficult work done.. but it is something that if you were doing it yourself, would make it a lot harder than doing a straight turbo install ..
Add to that, that you have to play around with wiring looms, custom fabrication of manifold , turbo up/down piping (as with any turbo conversion), fuel system upgrades (pump, reg., lines, injectors (optional)) , ignition system upgrades, strengthened clutch install, flywheel machine & fitting, tuning etc etc the list goes on.. I don't see how it is "EASIER"
With regards to Simon's (I8A-4RE) install, I have to say the complete opposite .. "just because Simon pulled off his conversion" it
does mean that everyone else will (or can) .. if Simon can do it, anyone can
Seriously though.. he has had some mechanical experience in the past, but if you're willing to take some night school welding classes & basic mechanical course then you should be fine with it.. his total came in at or around $6k & he still had to get some of it fabricated professionally..
OIL STARVATION:
I think someone mentioned this once & now it's the newest buzz word .. there's probably something about it on Sam's thread.. IMO, if you're checking the oil regularly & making sure it's not leaking / running low, then I don't see how this could be a problem.. The amount of oil the turbo can suck up isn't infinite.. and I doubt enough to suffocate the engine. I've yet to find any info about it that is definitive .. everyone's a bit vague on the issue, which leads me to think that it is rare & only cause issues after the engine has been running low enough oil levels for long enough sustained driving to severely overheat the engine components..
Simple answer - If you're doing a turbo conversion & are worried about it, put in a bigger sump, better pump, sump for the turbo, oil coolers or whatever you have to to avoid it. Same as you would do for anything else .. Murphy's Law 101.
I will go into more details about issues people (& myself) have
actually experienced with the 6a13 conversions later.. I'm tired.
I was waiting to see how long it took you to notice that 
you sure you can't just make 3 more hp out of it & bring it to an even 320?