Sorry if this is a real beginners question - is there any adjustment possible on the pressure output from a Facet 40105 fuel pump? Is it based on voltage? It is rated in various places from 2.5 - 3.5 psi and then other places at 3 - 4.5psi - but that being a range, how do you get a given pressure?

I've replaced fuel pump, disi cap and rotor arm, and without racing round my local village I've got no way of telling if this weekend will be a disappointment due to mechanicals or not (its more than likely to be down to my driving, but we'll see !

what pressure do you actually want? you'll most likely need a pressure regulator. theres loads of different ones out there.
filter king, sytec etc etc

There are at least different versions of the little solid state pump ( http://www.fuelsystem.co.uk/web-facet.pdf ) Webers like the pressure 2.5 to 3.5 psi measured with the engine not running but if the float valve is in good nick will cope with 4 psi. On carb systems if you can avoid addon pressure regulators do so (injection pressure regulators use a different priciple) select the correct pump to start with.