Lowest Static Drop (But Functional)

[Bmstd]

I am starting on a new project where we are converting C60 to C10. We have an original 8000 mile fire truck tanker and are repurposing cab, hood, engine, and transmission to assemble a c10 swb.

For the chassis we want to stay with static drop, but wanted to call on some of the experience out there.

What is the lowest drop that can be done and still be "driveable" using static lowering parts?

We want to stay traditional and not cut up frame (other than c notch) if possible.

Can anyone share what has worked for them or are using currently including what manufacturers?