I am working on a B-day present for my father whom is a Vietnam Vet from 68-69. He served in the 25th Infantry Division and I am told he was part of the 2nd and 27th Company B Wolfhounds.
Since I have limited space to spell this out I am wondering if anybody can help me with the proper
abbreviation and wording of this.
Thank you.

The proper way to abbreviate your father's military unit is:
B Co., 2/27th Inf. "Wolfhounds", 25th Inf. Div., or if space allows, B Company, 2/27th Infantry "Wolfhounds", 25th Infantry Division.
The "27th Infantry" part is his regiment. Their nickname is "Wolfhounds".

His company, Company B, is part of the 2nd battalion of the 27th Infantry Regiment, which is part of the 25th Infantry Division. The unit's abbreviation always starts with the smallest part of the unit (his company), and ends with the largest part of the unit's association (the division under which the company serves).

This unit designation stuff is something that often confuses those who have never been in the military. We get asked varitions of this question regularly. Hope I've explained it without belaboring the point.

I'm a bit late to the party, here, but I just wanted to comment. It's no wonder there's confusion among the uninitiated as to proper unit designations considering that the media frequently gets it wrong.

This includes websites that should not make these kinds of errors. Just this morning I read an article on the DefendAmerica website that refers to 3 elements of the 25th Division's 1st (Stryker) Brigade as the "2nd Brigade, 8th Artillery;" "3rd Brigade, 21st Infantry;" & "2nd Brigade, 14th Cavalry."

These are all clearly battalions, with the possible exception of the 14th Cavalry element, which could be a squadron.