Installing H815 Roms On H818 variants

Hey everyone , i last bought a G3 but then saw that G4 in my area dropped its price to under 350$ which is currently my budget , but its a Dual sim variant , single sim is now out of stock in my country and i really want to buy one , so i was wondering , IF
I CAN INSTALL H815 ROMS ON H818 or Its Variants ? Is It Possible ? Will Atleast One Sim Work On it ? :confused: