While Tom and I were musing over a pair of BX engine bays today, he pointed out to me the little red-and-white label to the reservoir side of the underbonnet - 1.65 on a 91 TGD, 1.35 or 1.4 (can't remember) on a 92 TZD Turbo. I was able to confirm on getting home that these are the original sphere bore specs, as he suggested.
Funny how you can fail to notice something right in front of you - I've never consciously noted these before.
Does this make me a sphere bore bore ?