I've completed the manual steering conversion. The box and pitman arm were new (reman gear I assume) from Speedway Motors. TRZ drop spindles 1.5" I believe, with TRZ upper arms and a TRZ bump steer kit. The brakes are Wilwood Dynalite small brakes to fit inside a 15" wheel. And am using a set of DA coilovers with 300lb springs (relatively light). I'm battling with the handling/drivability at the moment. I'm quite confident that the majority of the drivability issues are in the alignment.
I was expecting the manual steering to perform like all of the other manual steering vehicles that I've been around. This implies that it should require a fair amount of effort to turn at low speeds and then turn relatively easily once the car is under motion. Basically, drive like a power steering setup after I see 20-30mph and effortless steering at 50 mph+. The main issue is that the steering is heavy at speed on mildly sweeping corners. And the faster I go, the heavier it gets. It requires a strong grip on the steering wheel to make a 60-70mph sweeping turn on the highway. The type of corner that I'm referencing is nothing abnormal. I've put the front sway bar back on to ensure that removing it hasn't caused an issue - I intend to take the sway bar off once I get the steering sorted. I've changed ride height in both directions, raising the car about 5/8" seemed to help - I'm guessing the lighter springs needed a little more preload, but I could be wrong.
My alignment specs are as follows : camber is .75-.80 degrees negative; caster +2.5 degrees; toe -.3/32". I originally had the toe at zero and that was beyond AWFUL, increasing the toe in helped immensely in terms steering return and elimination of wander. I'm quite confident the camber is the issue. The reason I feel this is the problem is that the car turns effortlessly while backing up with one or two fingers on the steering wheel. Question : does this sound like a camber issue?
I have a G-body manual from 1980 and it lists off the differences in camber setting between manual vs. power steering. The manual spec is 0-2 degrees positive and the power spec is 2 to 4 degrees positive. This leads me to believe that I need less camber. I have some old school manuals for 67-72 GM trucks and for my 64 Buick, and both of those manuals indicate very similar differences in camber specs between manual and power steering.
Regarding the spill pan vs. engine diaper, I'm sticking with a diaper. To use an effective spill pan I do not see how it can be done without a rack and pinion steering conversion because of the clearance between the oil pan and stock steering cross link.
The steering upgrade is not following my usual budget of 'on the cheap' for most everything. But there is a story with that. Another member here offered me a new gear that he never used if I paid the shipping. After several conversations, he offered me his old brake and spindle setup because he was upgrading to a better, lighter I believe, setup. We struck up a deal for the price. And then the mayhem ensued with the shipping. The gear was 'lost' by Fedex, or I should say, they indicated it was damaged The damage was documented at the warehouse that is about 2 miles from my house. After visiting the warehouse and being able to locate the damaged package the stauts was changed to 'damaged and disposed of'. Like what the f@!**! ??? He was told by Fedex that Fedex believed it was a perishable good or some other BS. After going to the warehouse and seeing the element that works there, I'll wager a guess that it was stolen. But that is me and my pessimistic attitude (my wife says.) Regardless, I bought another gear and pitman arm from Speedway for $2__. The other member is yet to accept any money for any of it, which I'd be happy to pay 5 years from now - the world is filled with good people and I intend to pay it forward.