Just curious... I know you shouldn't have to and it's not right but.... what if you bored the pitman arm inside diameter say .010" and tried it again? Or, on the top side of the pitman arm machining/grinding a generous 45 deg angle around the splined area also allowing the arm to go further up the shaft allowing the use of the locknut? What I'm thinking is will this mod allow the arm to go up further on the shaft and allow the use of the locknut? 
How is the angle to the steering column when mounted to the k-frame?
One of my concerns with all of this is how does it effect the from end geometry with all these things not where they should be?
After reading this thread I went out to see if I was going to have the same problem with my small sector. I had not tried to tighten the nut yet...
Yup, the nut just got to flush with the end of the shaft. I tried a file on each groove of the pitman arm first
to slow.
Then I tried a little more aggressive approach with a die grinder stone on the hole of the pitman arm. The stone I used just fit with a little room to spare. Not milled or precision by any means but taking Brad's suggestion in a primitive approach a little at a time and R&R several times to get this result.
I should note that I tried an old original pitman arm and it went on further than the PST fast arm without modification but still not as far as you would want...
The 340 block and stock exhaust manifolds should make clearance less of an issue for me... I hope
The QA1 Tubular K-member should not change any angles.
Won't know about steering shaft angle/clearance until I get the car back form painting and take the time to make the front end swap.
I really prefer driving it to working on it in the summer.
-Randy
