[blimo]

Monojets work pretty well. They have good booster venturis. Re-build it to specs and make sure the jet needle's piston isn't binding in it's bore. Make sure the needle isn't worn flat on the side it rubs on the jet. Where you would go to get a new needle and jet to match your application is beyond me...

If you think it has torque now, just put a long tube exhaust header on it.

And if that isn't enough get an old intake manifold and split the siamesed intake ports into individual runners. (web search).

I had very good luck replacing the ignition points with an electronic ignition converter that retained the stock distributor cap (upgraded to one with copper posts - Standard Blue Streak..).

You could mess with the distributor curve, too.

Then you'd need a taller rear-end, or taller tires.