i was saying that if you're running 2 separate boost controllers it will be hard to determine which one is pushing more psi than the other unless you use 2 electronic boost controllers. with a single boost controller you'll have an even spread between them no matter the type. even if it spikes, it will spike evenly
for eg, 2 scenarios:
1st is the 2 boost controller setup.
lets say the boost gauge is reading 14psi. with 2 boost controllers you may not have an even spread as one turbo may be pushing 4psi, and the other 10psi. you cant tell.
this will cause one turbo to always be overworked.
but hey, at least you'll have 1 turbo in VERY good condition which you can sell to help with your rebuild.
2nd is single.
even spread, easily manageable. no dramas.
all you've got to do is get one of the vacuum hoses coming from one turbos wastegate actuator, then get a T piece and plumb it into the vacuum hose going to the wastegate actuator of the other.