Someone asked about rear bar mounting positions and if it is important. on another board.
Yes it is but in my opinion at times some people make too big a fuss over bar spread in it's priority of importance.
A correct set of rear 4 link brackets will measure shorter from axle center from top bracket holes and longer on bottom for bottom bracket holes.
This is because of mechanical reaction time of top vs bottom and because of mechanical force or leverage of top vs bottom which is a multiplying factor of how much torque gets appied to either bottom or top bars.
A correct rear 4 link top bracket will also have holes for adjusting Starting at bottom hole forward of vertical axle center and each additional hole will be farther from horizontal and verticle center of axle housing. Meanwhile at the bottom the bottom bracket will have all adjusting holes to be in a straight vertical lineeither at vertical center, but usually slightly forward of vertical center.
The longer leverage at bottom will react quicker but not as much immediate force. The shorter leverage at top will react slower but with much greater instant force.
So yes' It is important.