Carb advice

Months and months since my last post here, and I am finally getting ready to tinker again!

First, brakes I think...


But the engine build is not far off, and I am seeking advice this time---I want to use Yamaha R1 carbs on the new B20 build, and I have heard that Weber jets will thread right into the Yamaha carb bodies, eliminating the issue of testing scores of jets in search of just the right one. Hopefully that proves true! Besides fabricating a custom manifold to accept the R1 delivery, it should be a fairly easy adaptation, but there is one small thing I have heard can be an issue: the springs for the slides are set up to be very light to handle the insane throttle response and rev-happy nature of the Yamaha engine. Anyone know how to go about getting the right spring tension for the much more conservative Volvo motor?