Caster Mod for pre 73

[SuperDuperDoughnuts]

So I'll be rebuilding my suspension this weekend and I wanted to do this...

Bought bunch of new parts including new lower control arm shafts (Moog K6147). The new shafts have only a single locating hole--not two--that is 1.25" from the shoulder. The only other person (The Rocknrod) I see who had a single hole, says his were originally at 1.75".

I don't have power steering so I'm not trying to get to 6°+ degrees of caster, just ~4°. Basically confused at what I should drill at to hit my target.E

EDIT: Found some good info after more digging: http://67-72chevytrucks.com/vboard/s...&postcount=209