Hi Paul,
are your lines too far apart horizontally or vertically?
And how far - 1/8 inch or 1 inch?
Lets make sure we are talking about the same bracket - it is the one closest to the IP, correct? This one is asymmetric, that is, lines 6&5 and 3&2 are closer together than 5&4 and 2&1. See picture.
If your lines are too far apart horizontally then I would certainly try what you had in mind and loosen them a bit at the IP so that you can squeeze them together to fit the grooves in the plastic.
If they are apart vertically then I would first make sure that they are attached in the correct order. In the absence of any brackets, can you attach each line from the IP to the corresponding injection point without much strain in the line?
If they are in the correct order then I would fix the lines to the bracket first and then screw them on to the IP. The lines can be bent a little bit - with care and a gentle push!