just thought i would add on the prices on twinscrews,they are expensive for a reason,the precision required machining the screws and housings are out of this world,they are incredibly tight without any parts touching mechanicly. just very slowly turning a twinscrew with the originalseals on the inlet and outlet will suck the inlet seal in and push the outlet seal out. not made in china is and understatement.

there is twinscrews available for singlecarb applications aswell as dualcarb applications (dont realy know what the front carb does on those,it cant work to its full use.) and injection.