Bush hog 109 blade timing

[Frisch]

I have an old, really old model 109 bush hog rotary cutter.
I need some information on blade timing. I'm assuming that the blade carriers need to be set 90 degrees from one another.
Can anyone help in solving the blade/gearbox alignment question.
Thank you.

I also noted that on the inside lip of the stump jumper there is a concave fixture that might be used for alignment.

 

[Zebrafive]

Is this a two spindle machine? If so you want one one set of blades 90* to the other so they will not hit, assuming they overlap.

 

[rdbigfarmboy]

Look for loose bolts and the wrong blade length.