A kit (brackets and hardware) or a backhalf? Tube chassis? Ride height? How fast? Brackets need to be selected according to your needs and application. You need to know how the rear assembly will be configured. Some cheap street rod brackets may not have the correct geometry or configuration. Stuff we used 20 or 25 years ago is all wrong now.

To get an idea of the current thinking on correct hole locations and design, look at some of the better offerings at places like Bickel, RJ or McAmis. Housing brackets may, or may not, have provisions for shock mounts, wheelie bars, anti roll mounts, wishbone mounts, etc. Know where everything is going to be mounted. Chassis brackets can be made for specific applications like low, tube chassis cars, backhalf cars that sit a little higher, etc. The 4 link is a complete system and the relationship between the chassis and housing brackets has to be maintained. Chassis brackets have to be at the correct height, regardless the ride height of the car. Nothing is more frustrating than trying to tune one and there are no holes where you want to put the bars because the brackets are in the wrong place.

Bottom line, don't just "pick one". Talk to some people on the phone, tell them what you are doing and see what they recommend. Not just Pro Mod shops - places like S&W, ART, etc.