Ok Guys I'm getting ready to take my 8-1/4 out of my 73 Roadrunner and installing a 9-1/4. Can somebody walk me through this ?
The 9-1/4 had the perches cut off of it before I got it. I have new perches but I don't think they will work with the ISO mounts that I have and plan to keep. I might need to cut the perches off the 8-1/4 and re-use them. Welding them on is not a problem ( I'm a good welder)
The things I need help with are :

1. Setting up the car ( should the chassis be level ?)

2. When I set the rear end should the weight of the car be on the rearend with jack stands under the axle?

3. When I set the pinion angle what should it be ?

4. Where should I measure the pinion angle from ?

I have done this before but never paid attention to the pinion angle I just centered it side to side and eyeballed the pinion so it lined up with the trans and it's worked fine. After reading some of the posts here it seams that pinion angle is more important than I thought 20 years ago.