Lowering rear end

[old51sedan]

Ready to lower rear of truck by installing 4" drop springs. I know this had been talked about a lot, I also did several searches on it but can not find an answer to my questions. Have a 69 C-10 Sb, SS. Truck already has a rear track arm, do I need to replace this with an adjustable one or can I still use it. Just curious, but if it needs to be adjustable has anyone ever cut one in half and welded in an adjustable sleeve like in a screen door adjuster, only bigger? Also I understand I need to install a tapered (4 degree?) shim on each side by the trailing arm clamps to keep the pumpkin/driveshaft straight to eliminate vibration due to it being off center. I only want to do this once, but right also. Thanks, any help appreciated.

[CC69Rat]

A few things to consider. First, your original springs have likely sagged a little (maybe an inch) over the years of constant weight and work load. The new drop springs will be measured against a factory height new spring. So, in this case 4" drop compared to a new stock height spring. So the 4" springs will only give you 3-3.25" of net drop.

You mentioned the track bar. Yes. Anything over 3" or so I'd suggest replacing the track bar. They're pretty cheap, an adjustable one is your friend as all trucks are different in their own way.

You'll also need shock relocation brackets. If you don't, your truck will ride like a train car. Lowering the back changes the effective angle of your shock.. so they're laying more horizontal than vertical to do what they're designed to do.

3 degree shims for LWB. 4 dag for SWB will get you close but it depends on the truck really. You can also flip your front trailing arm brackets upside down to correct that pinion angle but it's a pita. Shims are easier.

Hope this helps

[dfosh]

Go to you tube and bring up Gibson 63 . He just did this on a 64 or 65 coil spring truck . He has a lot of good info on his channel.

[68c10airstream]

I dropped the rear in my 68 c10 sb and can say for sure that the porterbuilt panhard bar helped smooth out the ride. This kit gets you a new lower and positioned outward frame mount and a mount on the opposite side lower control arm area. The arm is adjustable with quality heim joints on both ends, and the tube is D.O.M. (drawn over mandrel). I believe this kit has about the longest bar possible, adjustable mounting holes on the ps control arm and if memory serves it's about $150.00. Not cheap but i would buy one again in a minute. Availability would probably be best through travis at AZPERFORMANCE.COM. If anyone can or will get it, travis will!!

As mentioned above, shock relocaters are a must and a nice gas shock like the monroe sensa-trac i use give a nice ride.

[old51sedan]

Thanks guys for the information, that's what I needed.