Any luck finding info on surnames changed post ww2 immigration?

Hey there!
I was raised by my great grandparent. My great grandpa came over when he was about 3yo from Poland with the family members he had able to leave with them at the time.

When they came over, whatever their original name was changed to *Pulhug.*

I know that some family members were in Poland after, and as he and the family members privy to that info has pasted on, I wanted to see if there was any way to figure out what maybe that surname could have been prior to?

To edit:
Grandpa: John P Pulhug
Brother Peter John Pulhug
Sister: Margret Pulhug

I know they came from Poland and ended up in Maumee Ohio

The family name was originally spelled Pulhuj Lucas Pulhuj wife was Eva Chiminski

Their kids John P Pulhug
Peter John Pulhug
Margret Pulhug
Paul
Isidore Pulk( went by Zig )
Jackie
@Pulhugged
you can hit me up at jdproject365@gmail.com and I'll tell you as much as I can.