i would step up your ve to 95% . and then add a bit for contingency , i would try for a 14-16 lbs/hr ,at 2/3rds of max flow, turbo sort of thing .
best thing about blow through is a) tickover is very stock ,with a suck through the fuel condenses and loads up a big slug in the housing at low rpm .b) best distribution.c)also , you can use an intercooler with blow through , i have a big one on the 500 , and i estimate it makes around 25 % more power .
,re blowing into a single carb ,then a log plenum ,with suck through the turbo mixes the fuel and air , so it has a better chance of staying in suspension ,and so getting a better equality of distribution , you wouldn't get this with the turbo> carb> log system , making a manifold that would feed the 4 cylinders evenly within the space available would be a challenge .
having said that ,my 400/4 with a suck through , and a box section plenum ,was great , just poor tickover and no intercooler ,, stil made 85 bhp when the clutch gave up ..you get a little bit of intercooling running the fuel through the turbo.
regards
robert.