Actually the stock manifolds came off easy.
I had the motor hanging so low, so that you could see the starter motor through the wheel well!

Like an angle of about 20°!

The problem is that the turbo manifols with 1 7/8" primaries are HUGE and so a couple of bolts allowed just and allen wrench to install them which takes a long time when you can only turn the bolt 1/8th of a turn at a time

That's the price for power I guess...
Also I had to "massage" the primary tube adjacent to the alternator as both of them wanted to occupy the same place. An oxy-acetylene torch and a hammer and all is good now.

(I also wrapped that primary with insulation to protect the alternator)
I told StreetFlight about the inteference and they will remedy that in all their kits.
We have pics so I will try and get canamSVT (thanks Ed, for you help) to post them soon.