You are lucky... Last time that happened to me, the guy at the junkyard had cracked the pump moving the tranny around... And then sold it to me as a good trans... I found out AFTER I put it in (and being very careful not to damage the pump when I installed the tranny) that it was damaged...
1996 gmc suburban 6.5 diesel 2500 leather etc etc 225k miles and counting
2000 K1500 Silverado Z71 ext cab short box 5.3 gas. 320,000 miles and counting Sold at 325k miles
1927 Ford Model T pickup. Bone stock 22 hp 4 cylinder. Driven to work on a regular basis...