I would not worry too much about the year until you know where the information came from, the point in this case there is no William Richard Clark/e born Liverpool 1874 +/- 2 years, the nearest is the one Carol posted.
Is this Susannah below? 
CLARK, SUSANNAH    mmn COOK  
GRO Reference: 1910  M Quarter in WEST DERBY  Volume 08B  Page 321
If so do you have the marriage cert for her parents, likely the ones below. That will give you the name of Williams parents.
Marriages Dec 1897  
William Richard Clark to Annie Cook
 W. Derby 8b 623
Colin