dust sheild bolts

I am a brand new owner of a 1988 f-250 4x4 with a zf 5 manual transmission, for what ever reason the previous owner removed the flywheel dust shield and did not put it back on. as the new owner i would like to put the shild back on but dont have the original bolts. Does anyone know what size bolt are use to attach the flywheel dust sheild to the transmission.
Thanks in advance,