Firstly, that is a fantastic looking rod nzsimon, a real credit to you.
Torque converter bolts have a captive washer(can't come off) & are M9 by 1.25mm pitch, total length is 18mm, shank length from under washer is 10.5mm, head is 14mm across the flats, has a 9 on the head & there is 6 bolts.
This is the best i can do without some photos, hope it is a help.