If it was just normal mild dominance and not a full fight, then you can attempt a reintroduction on completely neutral territory. If it is successful, then you need to clean down the cage you intend them to live in so it doesn’t smell of either piggy.
However, If it was a full on fight, then the chances of them wanting to be together anymore are low. You can try a reintroduction on neutral territory to see what happens, but if they aren’t compatible then it won’t work, And they need to separately permanently.
Your boys are both teenagers and if they can’t agree who is going to be dominant and the other back down to be submissive, then things won’t work out.
I’ve converted your cage measurements from inches to centimetres and can say that Your cage is also slightly too small for two boys to live in together, particularly those in their teens. Those measurements make it 120cm x 60cm. While that is the minimum welfare standards for two piggies, two boys need a lot more space than that to stop territorial fall outs. You ideally need a cage at least 150cm x 60cm for two boys. Ultimately though, space will only take them so far as character compatibility comes entirely first.
To live separately they will need a 120cm x 60cm cage each.
You also need to consider that the aggressor will always want to get back to the other piggy and be upset by a separation but it doesn’t necessarily mean the aggressor wants to get back because he wants to be friends and if is never the aggressors reaction you gauge it by. You always go by the one being bullied. If the one who was being bullied is happier to be away from the aggressor then their bond is broken and they are better off apart.
Do read the guides I have linked in below. They will give you plenty of information on whether it is worth even attempting to reintroduce them given their situation, how to do it an just general information about boar behaviour.
A Comprehensive Guide to Guinea Pig Boars
Bonding and Interaction: Illustrated social behaviours and bonding dynamics
Boars: Teenage, Bullying, Fighting, Fall-outs And What Next?
Dominance Behaviours In Guinea Pigs
Bonds In Trouble