you could run about 4lbs of boost and be plenty safe. But, if you don't want to use them, send them my way...lol
But, with turbos that small (you would have to use both of them), you would have almost no lag, however, you wouldn't gain much top end...low end though...they'd be similar to a supercharger as far as torque curve...which wouldn't be a bad thing.
Those turbos are actually often used on turbo 4 cylinders. A lot of people run a single T60 on v8s, as they are about perfect....so, a t25 vs a t60, you can understand the difference. Two T25s will still be a little less airflow.
But, putting one turbo on each side of the engine would net you pretty good power.
And, you wouldn't want to run too much boost as that can overspin the turbo.
The common thing a lot of people don't understand is, 4psi on a 318ci V8 is a lot more air than 4psi on a 110ci 4 cylinder. Meaning, to make that 4psi, that turbo is going to be spinning at about 15000 RPMs...where as, on a 4 cylinder at 15000RPMs, that turbo would probably be making 15lbs of boost.
So...run them low boost and you'll get a decent increase in power and be safe while doing it for both the engine and the turbo.
Also remember, with a turbo charger, you want absolutley no exhaust restriction behind, or, the least possible amount. Meaning, no cats, and large pipe (3"). The less restrictive the exhaust, the more efficient the turbo.
As I said, though, with these, don't be expecting 400hp at 5000RPM...you probably be more like 300hp at 3000RPM with a similar torque curve.
Also...don't forget a BOV...very important. And, do these have internal wastegates? Or will you have to get an external?
And...don't forget having to plumb the coolant and oil lines (if those turbos require that). Might want to get an oil cooler as well...along with an intercooler to make the boot even more power netting and safe.
I could probably keep adding things...but, those are things to think about for now.