We're changing a Gm 7.5 to a Ford 9". The brackets still need to be welded onto the 9". Was just wondering if there was an easy way to do this? Never done it before, Got the jist of it, but just not sure on the measurements. This is what we think we should do...

Unbolt all the control arms from the old housing

Bolt the new brackets to the exsisting control arms.

Put the new rear into place, square up the yokes and see where the brackets lay when put into place. And weld away?

What do you do about pinion angle? Its at 8* downward right now hanging with the 7.5 in it.

Any suggestions would help! Thanks

You've got the basics...

#1 don't fully weld anything until the car is totally set up and you know it's all square.

#2 weld each bracket a small amount at a time and allow to naturally cool before proceeding. So weld an inch or so on one side, move to the other side, etc... too much heat in one spot will warp the housing.

#3 check for straightness after you are totally done.

#4 be sure you are checking pinion angle properly. It is not the angle from the pinion flange to the ground...it is the difference in the angles between the flange and the driveshaft. So you need to measure the angle on both of them and then do the math. Also, ideally, you need equal but opposite angle on the front u-joint. Correct pinion angle is going to depend on how much rubber mounting you have in your trailing arms. 3-5 degrees is normally good... Probably closer to 5 is better.

Any other questions, I'll help the best I can.

Mike

Amen about welding and changing the shape of the axle tubes. Also make sure the rearend is at ride height. That angle changes drastically from ride height to hanging.