Im currently building a TT of my own design using T25 turbos and a fabricated exhaust manifold as the Janspeed Twin turbo design was not built for EFi (turbo too close to the plenum)

I thought of using 3.9 V8 "twin" cast manifolds (4>2) then take manifold forward and up to meet the Turbo(s) in front of the front cover.

Do you think this will be ok?

I know that the studs wont support the Turbos on there own so a bracket wil be needed.

Just to let you know of the plans so far............

3.9 V8 (if I find a bigger CC one I will use that)
Buick 300 heads (cast steel, big valves!!)
2 x garrett T25 Turbo chargers with waste gates
Twin "apposing" plenum (inlet each side)
2 x Intercoolers (300TDi so far!)
Meggasquirt
EDS (using Montego coils)
Electric water pump

Have you considered the DIY kit form tubular manifolds? You basically get the flanges that bolt onto the engine, and then a load of tubing and bends to cut to whatever length/shape you want and then weld it all up so it can pretty much go wherever you want it to!

Jon

have you given any thought how you will stop this 1,000+ bhp 2 ton behmoth (or have a large supply of fresh underwear )

how much boost are you planning?

Have a look at TVR 4.0l Griffith manifolds the face forwards to meet at the front collector box.

SG

Just fit a Chevy

5-7psi max