If the emblems are indeed correct,for the hood. A 250 series GMC, is a 1 ton. All 100 series 1/2 tons, 150 series 3/4 tons, & 250 series 1 tons, used the pickup style front bumper. The 1 1/2 ton, & larger trucks, used a channel type bumper. Most definitely check out,
www.oldgmctrucks.com , lots of good info. there. Join in on the Discussion Board, while you're there also.