I donbt understand...
People have an assumption that TWIN turbos automatically mean more power.
Those turbos he will be running are pretty damn small, the only advantage for going twins is boost at such a much lower level.
AKA.
I get boost @ 1500rpm(4psi).
His boost will probably start at 2200rpm, and will burn rubber nicely!
Unless he is running a 347 R block with some very nice heads, then I would recommend twin T66's LOL... then that is SERIOUSS HP!
Theres no real HP gains with twins...just boost time.
Not true with all cases, but with his, its very true.