In the restoration process of our 67 chevelle, I have added tubular upper and rear trailing arms and a 1" rear sway bar, arms with polyplus bushings (all from cpp). Here is my two fold problem: 1) the distance between the top of the rear axle and the frame is greater than the 5" the assembly manual calls for and 2) the sway bar is hitting the rear end. All parts were put on prior to the body being on the car and were tightened to specs (yes I got ahead of myself here). When we assembled the rear suspension to load it I had two friends ( they weigh close to 550# together) sit on a long 4 x4 wedged in the frame and we could not get the 5" clearance, it is more like 7-8". I know the body is suppose to be on the car, yet I would think their weight with the leverage of a 10' 4 x 4 would be more than the body weight.

Now to fix the problem with the body on the car, I would need to loosen all the rear suspension components and bounce the car several times to get it to settle down and then torque the bolts. Am I correct here? Also being 250#, I don't fit under a car like I did years ago, so can I place the car with jack stands under the frame and then using a floor jack raise the rear end till I reach the 5" clearance mark or not?

Any suggestions on how to solve these two problems would be greatly appreciated.

Thanks
Larry

Are you sure the rear springs are correct for your car?

To the best of my knowledge they are- they came from CPP and are RCS6435S which shows to be rear coil springs stock replacement. Also If I remember correct they where the same height as the old spring (not for sure that was 15 months ago). Hadn't thought about incorrect springs to you mention them.

Thanks
Larry

Did you install poly bushings at all EIGHT locations in the rear control arms? If so, that is more than likely what is keeping the suspension from compressing further. With poly bushings lubed and installed you can torque the bolts at any time, but the poly bushings themselves will create a lot of bind in the movement of the suspension keeping it from compressing like it should. At the very least, you'd be better off installing rubber bushings in the rear axle ears to provide a little more flex to the suspension.

Wow this is kinda funny I just did the same to my 66. I also used all CPP parts. I went with the Upper and lower rear tubular trailing arms along with their sway bar and springs. I'm not quite sure what you mean by it being greater then 5"??? What part are you talking about??? I to have the body off the frame. Then we installed a Moser 9" rear end. My Dad and I just put the frame up on stands and we had the rear end on a set of wheels and tires and just rolled it under the frame and then used a jack when needed. The CPP upper arms wouldn't work, so I ended up getting a pair of adjustaible Edelbrocks. They went in very nice. But I'm having the same problem with the sway bar touching the bottom of the rear end. I'm still waiting to here back from CPP on what they are going to do about the upper arms that wouldn't work. Did you use their front end parts as well??? I did, and I have some issues with them also.

Rich-L79- yes I used their high performance bushings (assume they are polyplus) at all 8 locations and I think I did lube them. Not a bad idea to go rubber on the ears. Thanks

1966BB4spdChevelle- I had to send back the upper's they sent the wrong ones (68-72) and they were too short (they repalced them with no problem). The 5" I am talking about is the distance from the top of the axle tube to the frame over the axle, as per assembly manual. When I discussed the sway bar with CPP, they said that they had found out chevelles took two different bars and to make this one fit drill two new holes above where it mounts to the control arm (don't remember the distance they said).They said when the body was back on the car the problem would solve itself--well guess waht it still touches. I am going to try and get the 5" distance between frame/axle tube before I call them out on this issue. Yes I used their front end parts and had no real problems that I remember other than getting ahead of myself.

Thanks
Larry

Wow this is kinda funny I just did the same to my 66. I also used all CPP parts. I went with the Upper and lower rear tubular trailing arms along with their sway bar and springs. I'm not quite sure what you mean by it being greater then 5"??? What part are you talking about??? I to have the body off the frame. Then we installed a Moser 9" rear end. My Dad and I just put the frame up on stands and we had the rear end on a set of wheels and tires and just rolled it under the frame and then used a jack when needed. The CPP upper arms wouldn't work, so I ended up getting a pair of adjustaible Edelbrocks. They went in very nice. But I'm having the same problem with the sway bar touching the bottom of the rear end. I'm still waiting to here back from CPP on what they are going to do about the upper arms that wouldn't work. Did you use their front end parts as well??? I did, and I have some issues with them also.

All 64-72 a-bodies use the same rear lower control arms but the uppers are different between 64-67 cars and 68-72 cars so like Larry experience they probably sent you the wrong set for your particular car. Regardless, the Edelbrock adjustable uppers are a very good upgrade.

Rich-L79- yes I used their high performance bushings (assume they are polyplus) at all 8 locations and I think I did lube them. Not a bad idea to go rubber on the ears. Thanks

1966BB4spdChevelle- I had to send back the upper's they sent the wrong ones (68-72) and they were too short (they repalced them with no problem). The 5" I am talking about is the distance from the top of the axle tube to the frame over the axle, as per assembly manual. When I discussed the sway bar with CPP, they said that they had found out chevelles took two different bars and to make this one fit drill two new holes above where it mounts to the control arm (don't remember the distance they said).They said when the body was back on the car the problem would solve itself--well guess waht it still touches. I am going to try and get the 5" distance between frame/axle tube before I call them out on this issue. Yes I used their front end parts and had no real problems that I remember other than getting ahead of myself.

Thanks
Larry

They told you to drill two holes in each arm that keeps your rear under your car and everything would be OK?????????

Time to throw those parts through there window and go with another brand!!!!!!

Here on the lower control arm bracket is what I am talking about, like 7/8" above the lower original hole.

Larry

LOL thats not as bad as I was thinking!!!! I thought they meant "through" the arm!!!
I would think lowering the rear mount and keeping the front in the upper hole would lower the bar more than lowering both mounting holes...

The 5" you are referring to is called bushing lock up distance. As I understand this is meant to be done with rear springs out of car as was done on assembly line. Once stock rear springs were installed and car was at ride height after final assembly it would be a distance of roughly 5" (+/- 3/8") from axle tube to frame. So the 5" number was pre-determined by GM so the rear control arms could be torqued prior to final assembly, at least this is my understanding.:)

Plus, the body will put far more than 550 pounds on the rear springs.....

My bad, I meant above the original hole.

size matters- if I understand what you are saying here is do the bushing lock up distance with the springs out, then compress the springs and install them? My only concern here is getting the springs seated correctly while keeping an eye on a da*n spring compressor.

Thanks
Larry

The chassis was pre-assembled at the factory before the body was married to it, thus it was pre-determined distance of 5" give or take 3/8" from axle tube to frame would be the distance at end of assembly process (full weight). This measurement would allow assembly line workers the freedom to torque all rear control arms in advance of rear spring installation and all assembly there after. If I were you I would loosen all control arm fasteners, bounce the rear of the car a couple of times and then let it settle, jack it up under the diff. and crawl under and re-torque all eight fasteners again. I would not get to hung up on the 5" distance as most springs being sold today yield a distance greater than the 5" in question. Hope this helps.

Well today I loosened all control arm fasteners and removed the shocks from the lower mount and had a friend (275#) sit in the trunk after we bounced the car several times and there is still 9" between the frame & axle tube, which I think is too much it has the shocks fully extended when the are on the car.

Two options that I see are - 1) lower the axle take the springs and assemble the bushing lock up like size matters said they did at the factory or 2) take the car to a frame/alignment shop, chain the frame to their frame machine and pull the frame down till there is 5" distance and then torque all the control arms and install the shocks.

Any ideas here, I am going nuts trying to get this done before we switch to big brakes and cannot use the 15" wheels, so the car will have to go on stands.

Thanks
Larry

Larry. Jack the car up. Put Jack stands under the frame rails. Loosen the control arm bolts, With the shocks unbolted, Lower the rear until you can remove the springs. (you may need to pull down a little on the axle to get them out.). With the jack under the rear, Raise the rear up until you get the tube within 5" of the frame. Tighten the bolts to spec.. Lower the rear and reinstall your springs. Raise up and bolt up your shocks. Put the car on the ground, YOUR DONE!!!!!