The turbos need to be above the
oil level unless you're going to rely on some kind of external scavange pump to lift the
oil back into the pan.
If you're turbocharging a 385 series, you obviously want more than 800rwhp, so you'll need a pair of turbos that are quite large in size...like a pair of T60's or something similar.
Take a look at a 385 based SPF. Those turbos all by themselves aren't going in the engine compartment; let alone the plumbing. So, they'd have to go somewhere else...like probably up in the nose behind the headlights or behind the tires in the front fenders somewhere. You'd have a real problem on the drivers side with steering, brakes, etc... I think you're going to have a major packaging problem. And, we havn't begun to talk about the plumbing/intercooler.
If you're willing to stick them through the hood and make a "log" style exhaust manifold, you could simplify the plumbing a lot and make it happen easier...but it won't be too pretty; unless that's the look you're going for.
A single turbo low and in the front would be an easier solution. Or a supercharger with a mount like mine. The same basic configuration could be accomplished with a single turbo and some front-swept exhaust that comes to a shared collector right at the turbo.
It'll tend to kill your exhaust note...turbos quiet an engine a lot. Be aware of that up front.
And, with a turbo, you'll need an intercooler. Turbos generally use smaller impellers spinning at higher rpms and create far more intake heat at a given boost level. Even at 8psi or so, I think you'll see 200+ deg intake temps without an intercooler; that won't work well.
Personally, after having gone the power-adder big-block route in a Cobra, I'd advise you against it. (A) It's ludicrous and largely unusable. (B) You can build a little 545 stroker with some A460 heads and make over 750hp to the tires on pump gas...how much power do you want?
My tires are on fire at freeway speeds at right around the 500hp mark (per my datalogger)...beyond that, I don't see the point except for the cool factor of having that capability. It was/is cool; granted; but the wow factor wears off shortly after you've done that a few times.
My stuff is at
http://www.racesystems.com/cobra if you want to look at it for ideas.
Oh, and I should mention...my car is an old West Coast Cobra. I believe the engine bay is longer than SPF by about 4-6", and there's a lot more room in the fender wells.