Porportioning valve question

I have found a porp valve from a Jeep Grand Cherokee that is almost identical to the 73-76 a body piece. But I think it is for 4 wheel disks. Can I use the Jeep piece with an adjustable valve in the rear drum brake line on my Duster, which has disks on the front? Eventually I will install 4 wheel disks on the Duster but that will be quite some time. If the Jeep piece will work for now it would save some trouble latter.
Thanks