Hello Eric,
I don't know the answer for certain - and by the look of it, neither does anyone else! - I don't think standard UT springs will make any difference (standard UT springs didn't seem very short or stiff) and may even be slightly higher at the front (due to the extra weight of turbo, intercooler, larger radiator etc.)
If, however, you fit springs intended to lower an Uno Turbo -40mm, they will lower your Uno Pacer by a similar amount.
-Alex