the biggest difference between the 34 pj and 35 pwk is the way the idle is set .the pj you set idle by turning choke knob and the pwk has a screw you set idling with.i ran pj's and ran pwk's ,they both work great.the pj series carbs are probally one of the best carbs there is for drag race in my oppinion.especially when set up on alky.then you have the pwk airstryker series that are an awsome carb .they differ from the regular pwk in that they have 2 fins cast in the inlet side that directs the airflow directly across the main jet and needle that helps atomize the fuel a little better,and they also have twice as many vents.oh and the pj uses an oval shaped slide and the pwk uses a flatslide.
heres a link ,check it out :keihin carbs