9502 UP Big Boy 4-8-8-4, #4019, w/ Experimental Smoke
9502 UP Big Boy 4-8-8-4, #4019, w/ Experimental Smoke,4-8-8-4 Big Boy (1941, After Cooler) Union Pacific by,Yamaha YZ250F/YZ450F Axle Blocks (2014-current) | Hammerhead,Simpson Strong-Tie CPFH09KT Crack-Pac FLEX-H2O Polyurethane,9502 UP Big Boy 4-8-8-4, #4019, w/ Experimental Smoke