welding spring perches

[Born Lucky]

OK here the scene.
Frame off and painted. Cab and other body parts stored.
Now I would like to weld in my spring perches but I am in need of info.
What the best way to set pinion angle to weld in the the perches?

[geezer#99]

You don't weld them on!!
Not yet!!
It's one of the last things you do.
You need the truck at full weight and sitting how it's gonna run down the road first.
You can tack them on though so they don't move around.

That's how I've done it.

[Born Lucky]

Yes that is what I thought. I have the skills but just never met this application. My first thought was that I needed the full weight on the rear end.
I was just thinking that if I set it up (mock it) I can get the right angle.
This thought came about as I have the engine and trans with driveshaft installed. Also I am thinking that the old leaf spring perches are a good start for getting the pinion angle.