Which model 420? (and I’m not sure what difference’s there might be)
I don’t have specs but this info may be helpful for you…
Lower triple
Part # = 44037-1048
Part Description = STEERING STEM
Model Count = 2
KX250-A6 80 250 KX250 MOTOCROSS
KX420-A1 80 420 KX420 MOTOCROSS
Upper triple
Part # = 44039-4004
Part Description = STEERING STEM HEAD
Model Count = 8
KDX250-A1 80 250 KDX250 OFF ROAD
KDX250-B1 81 250 KDX250 OFF ROAD
KX250-A6 80 250 KX250 MOTOCROSS
KDX400-A1 79 390 KDX400 OFF ROAD
KDX400-A2 80 390 KDX400 OFF ROAD
KDX420-B1 81 420 KDX420 MOTOCROSS
KX420-A1 80 420 KX420 MOTOCROSS
KDX450-A1 82 420 KDX450 OFF ROAD
Lower triple
Part # = 44037-1065
Part Description = STEERING STEM
Model Count = 6
KDX250-B1 81 250 KDX250 OFF ROAD
KDX250-B2 82 250 KDX250 OFF ROAD
KX250-A7 81 250 KX250 MOTOCROSS
KDX420-B1 81 420 KDX420 MOTOCROSS
KX420-A2 81 420 KX420 MOTOCROSS
KDX450-A1 82 420 KDX450 OFF ROAD
Upper triple
Part # = 44039-1040
Part Description = BRACKET,UPPER
Model Count = 3
KDX250-B2 82 250 KDX250 OFF ROAD
KX250-A7 81 250 KX250 MOTOCROSS
KX420-A2 81 420 KX420 MOTOCROSS