Sky65, I had the exact same problem with the present 1963 Corvette I have in the garage. The customer informed me that he had a regular 5 quart oil pan, so I proceeded to install the " Steeroids " conversion kit, thinking that I had all the proper components.
However the pan was the 6 quart version, and did not offer the needed clearance for the center R+P bracket. There are two way out of the dilemma, and both are time consuming. For starters I feel obliged to inform you that a disagree with your clearance solution of shimming the R+P forward 3/16" because it completely screws up the steering geometry.
The easiest and safest solution would be to replace the pan with a 5 quart version, be it original ( hard to find one in good condition ) or better yet, go with an affordable replacement ( check pic ).
If this is not an option, the only other modification is to remove the center bracket, and have a more pronounced bend made to it's center section.
Before removing it, measure the clearance from the rear bolt mounting flange, to the rubber accordion. Then have the angle in the center bracket increased up to the point where it almost touches the rubber seal. It's quite possible that it might just give you enough space to clear the tie-rod , lower A-arm issue.
Which ever you choose, rest assured that once installed, you will be thrilled with the new steering system, I know I am.
Stepinwolf