Here's the tool I made to hold the harmonic balancer in place. All materials from your hardware chain store monopoly.

1 x 1.5" diameter pipe floor flange,
1 x 1" steel pipe,
4 x 3/8x3" full thread bolts
2 x 3/8x4" full thread bolts to hold the pipe so all bolts end up the same height.
1 x 3/8 Drill Bit to drill one existing hole larger and drill 5 more.

Before starting this I though it would be hard to drill through that thick flange but compared to the much thinner steel pipe, it was like going through butter drilling the flange.

The black impact 27mm socket from HB fits right into the flange, although I filed it slightly for smoother operation

The tool bolts got bent a little after fighting 150lb/ft force. The manual says to tighten it to 148lb/ft and then 90*. Well after 148lb/ft I was only able to maybe do 45*. Just too darn tight.