This is an NOS Input Shaft for 1969 Chevelle & 69-70 Trucks with heavy duty 3 speed Muncie transmission. (not a Saginaw)  It is United Delco / GM part# 3932211 and is found in group# 4.351. This is for 3 H.D. speed transmissions and has 18 teeth.

Be sure to check your parts book before purchasing to verify fit.