No airbox usually means 45s for pilots, mains for K&N pods vary from 140 to 155. With TBS needles you probably need to look at the low side on the mains, especially if you're running a couple of shims. I'd check for vaccuum leaks around the manifold rubbers and while you're at it make certain the rubbers are on correctly.
Also, check the "squirrel condoms" for dry rot and finally chuck that hidden fuel filter at the common inlet point and put an inline filer on the fuel line where you can see it. Then you need to balance the carbs. I'm sure some of the others will jump in here and give you some sage pointers.
