Colin, there's a way to find a "close" setting before first flight...
Using a height-adjustable tank mount... Start the engine. Keep the fuselage centerline level. Roll the wings outboard tip down. Set an easy run. Tach (or listen carefully) and rotate the fuselage to "45°" either way. (... fuse centerline horizontal.) Then 'roll' it to the other side to the same angle You might - usually will - hear a change in RPM.
If 'richer' rolled toward upright, the tank is too high. Leaner indicates too low.
Stop the engine - nose slightly down, roll out board wingtip up - quick and safe..
Adjust tank height to oppose a rich or lean condition. Run your check again, shut down and adjust the tank again as needed. Repeat until there's little, if any, difference between "45°" rolled attitudes.
Why? The rolled attitudes simulate 'g' effects on the fuel in upright and level flight.. Pull (about 3g) and gravity (1g) act like a single force aimed along the diagonal of a 1 by 3 rectangle. It should indicate too rich (fuel pouring "downhill" to the needle) or too lean (fuel drawn "uphill" to the needle.
Our stunt pattern has inside and outside, moderate and sharp maneuvering 'g' loads.This wig-wag process should at least put the tank height near the mid point between the extremes. Final tuning can only be done based on in-flight observations.
The 1/4" high tank, ASIR, was most useful for side-mounted Fox Stunt 35s. Many other engines, not as fussy, ran well with the tank centered on the shaft centerline.