Grant Anti-Theft & Flaming River Shaft Q?

[Ed74]

I just finished installing my Grant anti-theft system and it works great! However, I have a problem regarding the spacing between the adapter hub/housing and steering column. At first, there was not enough room between the two, so I loosened the lower column bearing clamp and lengthened my WH Flaming River lower steering shaft. The gap was set to 1/8", though when I press on the steering wheel, my lower shaft collapses and I lose the 1/8" clearance. What can I do to prevent the lower shaft from collapsing, to maintain a 1/8" gap between the hub housing and steering column?

Thanks,
Ed