Buddy of mine just installed power steering in his 70 GTX, 440. He's waiting for Roger from the GTX registry to get back to him on factory alignment specs.
Told him I'm sure someone here has a FSM that could provide this info.
I have a FSM for my 69 Charger but not sure it's the same for 70.
TIA

Stock specs would be the same. But, if he's running radial tires, he ought to have more caster dialed in.

I've been pleased with 2.5 degrees caster, 0 camber and 1/16th toe in.

if he is using radial tires pretty much all mopars alignment specs for daily driving should be
1/2-1* neg camber.
as much positive caster as you can get with the stock parts.
1/16" neg toe.

The specs provided here are better starting points than the original FSM specs. I say starting points because that is what they are..starting points. Use them and then test drive the car for a few minutes. Then put it back on the rack and have the adjustments made so that the car drives to your liking. Or just goes down the road straight.

Every one of my cars have needed to go back on the rack after a test drive even though all the specs were 'in the green'. Often one or more specs are 'in the red' in order to get the car to go down the road straight. And I usually sit in the car or have my approximate weight in the car while adjusting the front end. Then there's the question as to whether to add weight to the passenger seat. All that will significantly change the settings.

And our cars will not usually come into spec without offset upper control arm bushings or modifying the rear arm of the uppers.

I've been doing alignments for a long time and this is where I would try to get it. I would split the caster a bit(little less pos on the left) to compensate for road crown

Yes a split is good areas with lots of road crown.

Last one i had done.
I think i had them get it as much NEGATIVE caster as they could. Then get camber as close to 0 or 1/2 negative as possible

I think you made a mistake in your post. Negative caster is the opposite of what you want.

Could be, been a while since Ive had one done

Negative caster tilts the knuckle forward and greatly reduces stability. The steering wanders and the wheel does NOT return to center after a turn. The faster you go, the more twitchy the steering feels...

with NEGATIVE caster
a great comparison is the front wheels on a shopping cart. they wander all over the place and never track straight.
yes they have EXTREME negative caster compared to a car but it gets much easier to understand what it does.