rear end swaps

ok. who here has swapped a caprice/SS disc rear into the 73-77 A body? aside from bolting up, is the parking brake a problem? does the proportioning valve have to be changed?

Pm Brownbomber AKA Dan, he has done it and also I can get my friend Joe to chime in here he just got one from him

Bill-Ray

As far as I know most tm master cylinders are 7/8 bore so your factory master cylinder is putting out the same pressure as the new model. The only difference being that the new one has an ugly plastic resovoir. I'm assuming you are talking about a disk brake rear end and in that case you will have to replace the brake proportioning valve to a disk/disk setup instead of the disk/drum in order for the brakes to come on when they ate supposed to.
The proportioning valve is a brass block usually located on the frame rail right under the master cylinder that all the brake lines go into. Also if u enjoy being able to tune things I would install one of the proportioning valve adjusters. It really let's you dial in the brakes to make the car more responsive and its still on my list of things I would like to do.
As for the brake cables when you get the impala rearend try to.get the e brake cables too it just saves time. What you do is you heat up the end where that fitting is that clips into you frame rails and twist the end off you old brake cables. After you do that measure out the impala brake cables and cut each one so that they will go to the factory location of your car. After you have them cut you take that metal piece and twist it back onto the new cable u just cut. What I like to do is take the actual cable and pull it into the plastic covering a bit so that its not affected by the heat or cutting until I get the metal end mounts installed. After I have the cables in the car I go ahead and cut the actual cable inside the plastic sheath to length. Then after your ready to install them buy 2 cable stops ,barrel nut, from any automotive store.adjust them and you will have an amazing set of brakes. An I guarantee you will feel a difference.
On the factory proportioning valve I drove around with the original for about 6 months before I chmged it and didn't have any problems but if you plan on going racing soon I would change it out before then.