the quadrajet will be sufficient for your engine. If you want more power, a cylinder head swap, and a cam swap will be helpful.
The engine probably does have fairly low compression though, so be careful when choosing cylinder heads and cams. If you want a high-perf camshaft you'll need to build some compression, and smaller combustion chambers are an easy way to do so. However, don't increase compression too much or you'll have other problems.
I'd say, first figure out what kind of heads you've got on there and try to figure out how much compression you are running.
- '68 Chevy Camaro (sort of done, but always subject to improvement)
- '63 Pontiac Tempest (work in progress)
- '72 Datsun 240-Z (back-burner for now)