Malc
Dunno about thrust bearing fitment but if you are worried about size and clearance look into dry bearing material coated washers, Glacier, Igus et al as these can easily be trimmed down to size. Not up to speed on the latest breeds as its nearly 30 years since I got my stock of Glacier ones but they are effective and give a roller thrust a trot for its money. Obviously not as free as a roller or ball thrust but certainly well up on the good enough side of she'll do.
Best to use coated washers as some of the solid dry bearing materials are fairly limited in load capacity before they start to squidge. I really don't know about modern filled varieties.
Clive