retard timing mechanically?

I rigged an adjustable timing set-up on a Hemi once...worked perfectly. I used a choke cable and installed two set screws in the base of the distributor that would limit total advance/retard to something like 10 degrees. Choke cable all the way in was -5 (I think base timing with the locked distributor was 32 degrees.) Choke all the way out was +5. Had the distributor hold down shimmed so that it would allow easy movement, but held the distributor down in the hole. If you try this, make sure you use an O ring type dist. base and not the flat one that takes the gasket.