i’am a size 43 in shimano, although on the large size and 42 are too tight, so what are specialized shoe sizing like?
Also my feet are more narrow than wide, what are the width like on specialized?

I find Spesh shoes are spot on size wise: I’m a 43 generally and a 43 in Spesh, whereas for Shimano I size up one size, so a 44.

I’ve found specialized to be pretty accurate to “normal” shoes.

Yes, I’ve found the sizing to be very accurate according to European sizes.

HOWEVER a few years ago, they made a mistake on the labels, which showed an incorrect UK size. For example, EU 38 was also labelled as UK 6.5 (actually UK 5.0), and EU 39 was UK 7.5 (really UK 6.0).
I mention this just in case anyone is buying off Ebay. I got some fantastic bargains of unworn Tahoe shoes 😀

what about width guy’s on them as my feet are quite narrow?

Wider than Shimano.

I use them and have skinny feet and they are all good, best fit for me. 44 is a 44 as well