The last Tisco sleeve and piston kit i recieved had a change to the way the sleeves were made. there was very little taper at the bottom of the sleeve, so little in fact that the sleeve would not start into the o ring.
i thought about grinding a taper on each sleeve but discarded that idea as crude, time consuming and could potentially damage the o rings.
i thought about returning the product but that does not get the project completed.
so what i hit upon was to cut off the taper from one of the old sleeves, clean it up, and use it as a lead in guide to expand the o rings. with a little vasoline it worked perfectly.
Hope this helps someone else.