Stepper motor unipolar "Lin engineering"

Hi!

I require your help regarding a problem I’m encountering.

i m looking for a stepper motor “Lin engineering” not aking anymore
It’s the control of the cable of the caburator of my engine boat, it’s a speed regulation.
The stepper motor is
nema 23
6.35 shaft with flat
4.08V 1.6A
Unipolar, 6 leads

I found some good option but voltage are different is it a big problem??
for exemple one is 7.5V and 1A by phase

Thank you so much for your help and sorry for my english i m French

Etinne
Allereau Etienne
Thank you so much in advance for your help!