Power Steering Question?

[chopnchaneled]

Still a noobee here and these trucks.

I have a 68 C 10 stepside and doing up grades along the way, so far i've lowered it 4 and a half in the front and five in the rear, Replaced the 250 inline with a 350, replaced the 3 speed with a 700R4, oh yea disk brakes in the front.

My latest update is power steering. My truck is a early 68 so no divot in the
frame to clear the larger power steering sector. had to space it out 1/4 inch to get it to clear. "Now mind you i had a lot of play with the manuel box" the
replacement box is very snug "no play". Whats happening is when going down the road it feels twichy to me, is it normal or am i just over driving it due to all the play that i had in the old box? or is there some kind of centering
valve in the steering sector that is off due to shimming the sector?
any advice would really help