Is there any way to set up new leaf spring perchs with the rear out of the car. 69-12 bolt posi.

The best way to do it is to find another rear end and get all of your measurements off of it. A 10 bolt will be the same. The pinion angle and spring location are controled by the spring perches, so they need to be right.

I don't have easy access to another rear, do you know if blue prints might be available?

Using an angle meter, the bottom of the perches should be between 28 - 31 degrees negative angle from the cast webbing on the center piece of the differential. I just put new perches on a 12 bolt and used those angles taken from the 12 bolt under the 69. The diffenential should end up with a 3 - 8 degree negative angle from the driveshaft. It sounds a little confusing but when on level ground and under a normal load, the spring perches actually pitch forward 28 - 31 degrees more than the differential At the moment I don't remember how far in from the axle housing flanges they are but I will measure it tonight. The rear is sitting on stands ready to be installed so it won't be difficult to measure.

Ok, I had a chance to measure. The perches are 3 inches from the inside of the axle tube flange and measure 42 1/2 inches center of perch to center of perch.

Thanks for the great info on the spring perches.
I'm a little confused as to where you are putting the angle meter, on the cast webbing? , beside it, across it. I understand the perch angle you are describing, but not sure of the angle measurement from the center piece of the diff. Thanks again.

I use a small meter with a magnetic base. Place it on the web that is parallel to the pinion. The angle is taken perpendicular to the axle.

Thanks for the info.
Did you use the stock camaro perches. I was looking at a set of moroso flat plate perches, I thought these would be better for future traction bars.

If you intend to use Lakewood slapper bars that have the lower spring plate or slide a link's you need to use the Camaro perches either multi or mono leaf. You can buy new ones from any Camaro parts supplier. The flat perches are actually made for Chrysler design mountings.