The point of Hi-los is to set each wheel individually. The suspension parts
may be new, but the car isn't, and may not be perfectly straight. Ride
height impacts all the other parameters, so first set the height with the
Hi-Lo kit at each wheel, that take it in for a geometry check.

I'll try to add some things that others haven't said, though they have
given you plenty of things to check.

I've driven several cars with at least 3/4" height offsets and they
haven't had any tracking problems. So, height probably isn't directly
the cause of the pull.

You might have a brake problem. The driver side brake would be
sticking on. This happens with discs when a caliper piston sticks. Any
type of brake can suffer this when a flexible hose starts to break
down. The inner part of the hose becomes a one-way valve and tends to
lock the brakes on. Sometimes it's interrmittant, sometimes it's
constant. These hoses tend to break down when they are disturbed by
doing other suspension work.

It's going to take more than 50 miles for the suspension to settle
down. It should be enough to get the knuckle joints, cones and rubber
springs to seat. Everytime you disassemble the suspension on a Mini
these three pieces have to work themselves back into a single unit.

This is a good time to even every thing out. Set the overall
suspension higher than you ultimately want it. Three quarters of an
inch higher is probably about right. In about a year, with regular
driving, the suspension should be very close to it's permanent height.
This is what you have to do anytime you install Hi-Los. Keep in mind
the 3:1 front ratio between the car height and Hi-Lo  adjustment. It's
5:1 for the rear. Count the number of threads per inch on your Hi-Los
and you should be able to calculate the number of turns or partial
turns needed to move the car height the desired distance.

I'm told that Rover introduced a new rubber spring in 1998 and that
these deteriorate very quickly. Hopefully, you didn't get a set of
those. If you did you'll probably end up changing them again in about
4 or 5 years. The early cones seem to have an incredible life span.
There are a lot of 30+ year old cars here in the U.S. that perfectly
functional suspensions.

Good luck,

Kelley

These symptoms are typical of worn track rod ends or play in that area such
as a loose steering arm. I would check that the car is in good condition
before blaming the new components.

John