Re: Squires rear turbo system.
In my opinion 5-7 lbs of boost isn't too much for a stock healthy engine to handle. Go more than that and you need to start thinking about stronger internal parts if you want the engine to be reliable.
I've built a few supercharged engines and all have held up running anywhere from 5 - 12 pounds of boost.
On my Camaro (stock 305 engine) I was going to use an FMU (fuel management unit) but got an adjustable fuel pressure regulator instead to boost the fuel pressure up. Ran great and made the car a little bit more respectable on the street.