Do you know if it has A1 heads on it? Someone has swapped out the intake/tbody for the A3/4 style. Maybe they swapped the heads too. The intake stuff will physically bolt up, but the ports aren't the same shape/size.
We've got one of these at work. Welds good and hot. A little finicky on the thin/sheet metal stuff. But, GTG other wise.
We also have a few of the newer digital 252 Millers. The old guys in the shop prefer the 250...