Pahelp mga idol. Change block. 63mm to 59mm

Mga paps ok lang ba magpalit ng block from 63mm to 59mm?

Ito po spec ng motor
*Crank static balance
*bore 63 steelbore twh taiwan
*mtrt head
29.5 -25valve
*3 angle valve seat.
* high lift cam touring specs 7.2
*All out png gilid
*Gearings 14-41
*carb 28-

Thanks in advance.