Shouldn't cause any steering issues, as the steering parts are not being moved in relation to the subframe.
Yes the steering box will move up in relation to the column when you remove the bushings. and the alignment will be foo about .800. you would have to adjust the column at the firewall and possibly the dash to get them to line up again
Also fan to shroud clearance will be less at the top. Distributor to firewall will be closer. If you have a flanged bellhousing like Lakewood, the older bellhousings have a wide flange near the throttle arm and it may hit. Air cleaner will be closer to hood. Trans crossmember may hit floor and you will not be able to remove it without separating the sub from unibody.
Steering column will need rework.
Check your clutch shaft if manual clutch.