Helpful article
https://www.minimania.com/SUSPENSION___Basic_set_up_method_1048

I'm embarrassed to admit I did not know castor was adjusted by lengthening and shortening the tie-rods. I replaced my tie-rod bushings a couple of weeks ago and reinstalled the rods without regard to their length. Turns out the rods were on the short side at 13 7/8"  This afternoon I readjusted the rods to the recommended 14 5/8" [link]. I also discovered that the driver's side ride height was drooping slightly so I took care of that as well. All that lead to having to readjust the toe and camber. I ended up with .5 mm of toe out and will probably leave it at that, although I miss the crisp steering the negitive toe had given me.

My steering is a little heavy, 13 X 8 rims.  It does chase irregularities in the road sometimes, but runs straight hands off on a smooth road.  I'm going to take it to an alignment shop and see what it is currently.  Was looking in the shop manual for stock settings, your post makes me wonder what is a good setting for street and a little autoxing?

Castor, as with toe and camber, is not a fit-n-forget setting - all three are inextricably linked and also to rideheight, adjust one of the four elements and the other three need to be checked and adjusted to compensate.

You may find that your change isn't just down to the toe angle.

Castor is 3° positive per Haynes. I had it set at a Mini-friendly alignment shop as I have no way of measuring it myself. 

And CooperTune's question about caster is important.

Toe in on a FWD car tends to make it Gocart..dart about from too easy steering.

I have been playing with settings for a very fast street car. On 5.5 x 12 rims and sticky Yokes running a lot less camber front. Toe in tends to make a little quicker off center. What is your caster setting? I'm just completing a Historic Rally car from UK. 6 x 10s with sticky Yokes. Looking forward to test driving. Coil overs very trick. I can text pics if some one want to post. Steve (CTR)

Front wheel drive...front toe out. Rear wheel drive...front toe in.

Following general guidelines and conventional wisdom regarding alignment settings, I’ve been reasonably happy with my alignment setup. I carry 1.5 mm toe-out and 2.5° negative camber on the front, and 3.0 mm toe-in and 1.5 mm negative camber on the rear. Although it’s impossible to quantify without comparing lap times or driving other Minis, my car seems to handle well, track straight and tire wear is even, all without a trace of torque steer (yea!).

I installed new tie rod ends the other day and of course had to reset my toe settings. Using my toe plates which measure total toe only, I had to do at least a dozen short test drives to center the steering wheel and get the car to track straight. In the process I discovered that with a tiny amount of toe-in, the steering seemed more nimble—that is to say it turned in better, seemed livelier and steering effort was significantly reduced. Overall, it feels as if communication between the front suspension and the steering wheel has improved, similar to a couple of 911s I’ve owned.*

As I understand it, toe-out improves high speed stability, yet with a bit of toe-in, my car still tracks true and isn’t wandering at highway speeds. I have noticed that it is somewhat more sensitive to road crowning—drifting sightly left or right depending upon the angle of the crown. On a perfectly flat surface, however, I can let go of the steering wheel for a considerable length of time without having to correct. Unfortunately, I have picked up a bit of torque steer, but that’s a small price to pay for what seems to be an overall improvement in handling and steering sensitivity. Any thoughts?

*An automotive writer, trying to explain how much improved the 911’s steering was compared to the previous year wrote, “Porsche’s steering has always been legendary—you could practically tell if you were to run over a dime. Now you can tell if the dime is heads or tails.”