wanted to get peoples input on converting a ford 9" into a chevy car.....we've got some ideas but wanted to see if there was a better way or if we are even on the right track.

I would HIGHLY recomend clamp on leaf spring pads (if they let you.)  Every once in a while it's not a bad idea to knock one loose to take out any preload that happens due to springs settling or flattening out.  Also you will be able to mess with your pinion angle a bit.  You will still need a 1 inch stitch weld on the bottom because they'll probably move on you over time.  Don't get crazy with the welds though. You need to be able to knock it loose.  I wouldnt go smaller than 60 inches on the width otherwise the brake gets tight on the u-bolts.

When I set the pinion angle I put the car on the ground with the clamps/u bolts barly snug so the rear end is in 0 bind and can move freely up and down.  Then I move the pinion up or down to get the spec I need. When I like it, I tighten it all down.  You need to recheck it after you tighten it to make sure it didnt move on you.  Then you can add a stitch weld to both sides.   I would set the pinion down 5-8 degrees for starters.  You can add more but you start to wear on the joints pretty bad.  Don't worry about what's on the old car.

If you dont have clamps, you still do it the same way by keeping the u-bolts barely snug.  One you weld it, it's hard to change hense the reason I suggest using clamp style.

If your working a coil car this has nothing to do with your setup other than maybe the pinion angle reccomendation.