You can pull some BIG hp from the old carbie donks Some original photos have not been recovered yet.

And what are some people with later models doing to get more out of thier cars? That's right, going carb.

Countless examples of getting big HP from a carb set up just look around. One more stand out would be the latest summernats Horsepower heroes ute, 532ci turb donk pumping out 2000HP on a SINGLE modded 4bbl dominator

i think barry grant is still using them on his vehicles and they seem to go alright.

Active are no longer producing manifolds...and yes they were a single plane design. vlcalais8 is pretty much on the money, sounds like you are chasing a mild setup, keep your VL heads, shave them and clean up the ports, throw some springs on them etc. The chambers are 57cc standard 40 thou off would bring this to around 51cc. That would be enough before you would start worrying about valve to piston clearance with a standard motor. Slide a crane 286 cam, they are proven to work very well with this kind of budget setup, chase up either an edelbrock manifold or mod your factory one, you can stick with the quaddy or go with a vacuum secondary holley (600cfm would be ideal for this setup) Set of extractors with a decent exhaust, this kind of combination will yield typically anywhere from 140-160rwkw depending on bottom end condition. Good for 13's with the correct diff ratio and hi-stall. Its a nice, proven, budget setup. (btw if you search enough you would probably find a complete running motor with the same mods for the same price.) Something to think about.