Shane, Ok forget such things as blow through. Knowing the exisitng system I can't envision how to seal the plastic filter housing. Assuming you did the problem becomes your CIS is totally clueless once the manifold pressure goes positive.
What are your skills? If you can cut and weld a tube a grassroots guy can do this for less than $500. You'll have a mild boost compatable with your high C.R. and a very responsive motor. Nowadays turboing a motor does not require a huge a
outlay of $.
The Grand National T3 has a special turbine inlet foot.
My 3.0L had twins fed from the stock HE side collector flange. One turbo was in the CAT location and the other in 930 Turbo location. The side unit drained to the valve cover and the rear to the chain cover. Here is a shot of a 930 Turbo (3LDZ)unit lifted to drain into the chain cover. Required a simple modification of the rear mount.