Hi 67mann,
First Question: do you have the correct installation kit for Truck? (PN 3285)
If you have a mustang etc installation kit you might ran into some problems.
I recently installed a Grant wheel on my 68, but I swapped the column to a mustang column and so I didn´t had this problem.
What comes into my mind on your issue:
here is a comparison of a truck column vs mustang column:
Truck
mustang
as you can see, the distance between the bearing seat and the hub seat is different. the distance on the Truck is about 0.2" more than mustang. Second issue: the mustang column is tapered after the hub seat, and I think the grant hub is tapered on the inside too, but I´m not sure about that..
If I remeber correct, there is no specified seating area for the bearing and no snap ring on the truck column, so you should be able to move the column housing inward the cab.
You definitely need the horn brush pressed down a bit to have good contact! Install a horn relay if it isn´t already there to keep current minimal on the horn brushes.
There should be another issue with the turn signal canceling cam mechanism or is it missing? I remenber to pins which are punched into the bottom of the grant hub. They have to reach the canceling cam on the turnsignal switch...
For the cover I think you should contact grant. Even the outside diameter of the cover seems a bit to small for your column.
long story short: I think you should try to move the column housing to eliminate all 3 problems
Chris