Replacement of impeller doesnt fit 3593658

[pmar]

Hi I have small problem, on my Volvo penta d2-40B engine, I want to change impeller, bought spares from 2 companies dedicated to original PN 3593658, difference is that spares have threaded shaft inside which doesn't fit the nest (difficult to measure but seems same as original one.) I cutted wings from old one to check and it fits easly, am I forced to but original ones or there is some trick that i dont know about? I fear that if I will fit it by force I will be unable to take it out in future...
https://i.ibb.co/P4rmhtZ/20230915-142408.jpg <-picture

spare: GIRANTE ANCOR 2046 X VOLVO PENTA - 4318118

[team karst]

Not sure this is your issue but i had a go with vp vs jabsco impellers. One had 12 mm id bore, the other was 1/2” (12.5 mm). Otherwise same.