You just need 3.5 Psi for the Weber. Although I use 6 Psi in the race car. And some carb tricks on top of that. 

Hi Lynn,
do you have any ideas on methods to lean a weber, or any carb for that matter, for altitude mixture adjustment. I have heard of a vacuum line to the inlet manifold thru a needle valve to the fuel bowl, then vary the pressure head in the fuel bowl. And, jetting the carb at sea level with the choke on, and then backing off the choke as the airplane climbs.
Any comments or suggestions?
BR, Dave McC