Every 4BT ever made is turbo charged. Hence the 4= 4cylinder B= B series T= turbocharged breakdown of thier namesake. The 4B engine would be a non-turbo.
They have different ratings because they were ordered that way. The 4BT wasn't made in a 130 HP rating AFAIK, the 4BTA was though. The factory ratings don't mean much. Turn a couple screws and you've surpassed 105 HP by a long shot.
From Cummins "Troubleshooting and repair Manual for B3.9 and 5.9"
The 4B's made as little as 54hp, up to 80hp, highest listed hp for a non-turbo.
4BT's range from 86hp to 110hp and the 4BTA goes to 130hp with a P pump. The highest hp listed for a VE pump is 120hp.
If you have the pocket book for it, the ISB4 makes 170 hp, but this is computer controlled.
Not to mention the 250hp P pumped marine 4BTA.