davey,
Sorry for the late reply. I was taken suddenly quite ill, but am recovering nicely. At least I'm back here at the googlebox. No, it doesn't matter whether there is weiight on the system when you check the rack bushing. It sounds like yours are fine.
It's interesting to hear that there are others working on a tapered roller bearing solution for the Spridget. It is long overdue. When we did the Bugeye we are finishing up, we used both the Winner's Circle kit and a special new set of spindles with extra hard stub axles. The point here is, by using tapered roller bearings alone you will make an improvement, but I hope the system chosen also uses (unlike most cars) the conical spacer and shims. Some think this is just a bother, and no longer needed when tapered rollers are used, but I disagree. Here's why:
The Spridget stub axle in standard form is pretty small in diameter, and therefore, regardless of how well made, is a bit flexible. This is something you'd LIKE to fight, for many reasons, not the least of which is the way it can cause brake pads to push back away from the rotor and result in a lousy pedal requiring pumping. A hardened stub axle will help in this regard, and is a virtual neccessity in racing. But, you can go a long way toward the same rigidity by simply using the spacer and shims, torqued properly, and leaving just precicely the BEARING clearance indicated in the manual to allow for heat expansion. What happens is that the base of the stub axle at the spindle, the inner race of the inner bearing, the spacer and shims, the inner race of the outer bearing, the thrust washer, and the axle nut, when torqued to specification, form a secondary column of strength surrounding the inner column (the stub axle). This increases the bending strength of the entire assembly LOADS. So, the ultimate is to use tapered roller bearings, which are far superior to thrust ball bearings in this applicattion, and retain the spacer and shim set-up.
Forgive the diatribe. We've had MGBs in particular come into the shop with no spacer fitted (MGBs have tapered rollers from the factory, but indeed also use the spacer and shim method to strenghthen the assembly) and sagging or bent stub axles. As you can imagine, the correct repair is a front suspension overhaul with good serviceable swivel axle assemblies. That's a pile of mula that didn't need to happen.
It's worth a thought.
Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon