Just an FYI - I picked up a set of the Quick Fuel / Proform 4-emulsion hole "race" metering blocks along w/ one of the new aluminum Quick Fuel / Proform "950" 1.45" venturi x 1.75" throttle main bodies and figured I should pass on my observations.
Main body
1. Casting quality OK, although the finish machine work on the metering block surfaces is fairly rough and should definitely be used w/ a highly conformable gasket, rather than a harder (more durable) one that might not seal the irregularities as well.
2. Booster alignment / centering looks decent, but the actual machine work of the boosters is lacking, IMO. The taper from the top inside of the boosters isn't consistent from piece to piece and the insides of the boosters down to where the step for improved fuel shear is machined can be a bit "crusty." You can go onto Summit's web site and look at their nifty "360 View" pictures of the Proform 950 main body and QFT 6-950 (or is it 950-6?) which are the identical parts sold by both and actually see the same issue w/ their display models.
Metering blocks
3. These metering blocks are the ones that have the emulsion holes pre-drilled, although you can open them up if you choose and use screw-in bleeds. The as-delivered emulsion holes are supposed to be .028" on all holes from what I can find out (which isn't from Quick Fuel's Tech Support which neither replied to my voice mail nor responded to my requested e-mail more than a week ago), but when I gauged them there were random sizes of .024", .026" and .028" on both blocks. I've since set them all to .028".
4. Not sure what size the replaceable PVCR restrictions are supposed to be (see "lack of response from QFT" comment above), but I can tell you they're drilled about 3/4 of the way through w/ .059", then shrink down from there. Also, they're not drilled straight and opening them up all the way to .059" would start to broach the threaded area on the sides of two, maybe three of them. I've since taken new blank bleeds and drilled a set of new (straight) ones.
Keep in mind that these are the same parts that Quick Fuel uses in their Q-series carbs and Proform in their "race" series. I hope they do a better job of addressing all this "stuff" when they actually build carbs using their own parts than when they sell them to customers who might actually expect them to be machined properly.