[lust4speed]

Anyone have the sway bar bolt hole spacing measurements on the control arms from the rear bushings on a 65 Catalina? I received my new rear sway bar from ADDCO and placed it in position to test the fit and really don't like how far forward it had to go to make contact with the control arms. The bar ends up about 3" forward of the diff cover, and most I've seen end up about under the cover. To bring it back will require 3/8" to 1/2" spacer plates on both sides of the bar between it and the control arms to space the bar back where I would expect it to be. It would be handy to have hole spacing specs in hand when I call them to see why their bar fits funky.

Was thinking this was going to be as easy as it has been on the A-body cars we've added the bars to, but looks like this will have a few hurdles to get over. Got the spare set of arms all cleaned up but don't want to bugger them up with holes in the wrong places.

[misterp266]

I found the same issue on the sway bar position on my ‘66 Catalina. Too far forward, looked wrong. I never ended up installing it but it seemed like the spacers would need to be thicker than 1/2”. Yes, Addco. I only put the front one on and it made a world of difference.
The best setup is from RARE. Comes with HD arms as well. Not sure they still sell it though.
I’ll be watching to see how you make out.

[70ra455]

There's no hole for the sway bar on 65-70 full size cars because they didn't come with rear sway bars. You can use the sway bar AND brackets from a 71-75 Bonneville and then drill holes in the control arms.

[lust4speed]

Well, you're not wrong and I'll rephrase the question. For those of you that have mounted a rear sway bar to the lower control arms of a 1965 to 1970 B-body or have a 1971-75 Bonneville with a sway bar - what are the locations of the holes? Or I could use a measurement of the distance across the bar width at the front and rear hole locations.

To restate the problem, the new Addco bar slides forward between the two control arms until it is about half way on the arms, and that sucks. The bar crossing about the diff cover doesn't have much influence on rigidity of the arms since the bar would be very close to the rear bushings, but getting halfway up the arm will probably lead to some heavy torsional stresses on a part of the arm that isn't designed for that type of load.

[rustyrelic]

I copied this idea, using a mid 70's Cadillac rear sway bar. Worked well.http://www.nitemareperformance.com/B...bar%20kit.html

[kalvert]

did you ever end up getting the addco installed? Also was it the 2419 kit?

[lust4speed]

Yes, now installed but car is not on the road yet. I don't have my paperwork in front of me but believe the Addco number is K2-419-00-726 which is a 1" rear bar. They also list a little different number for hardtops and sedans with the last three numbers being 725, but the specs are the same. The bar was 1" too narrow and 1/2" plates welded to each arm had the bar back and centered under the axle tubes. While I've simply used 1/2" black pipe as spacers inside the arms on other installs, this time I cut some 1x2 bar stock and tacked them in place.

[MPKind]

I've been researching rear suspension parts for '65 and there's not a lot of options. I'm upgrading my stamped steel rear bars to PMT Fab ones. There is no other source for aftermarket rear control arms...that I've found. UMI or QA1 don't have anything for these cars. As for the rear sway bar, it's the 70s BOP B-Body GM part with the horizontal mount that literally only fits in one place inside the lower arms (or can be moved around using inside adaptor brackets), or the Addco vertical mount bar p/n 2419, which appears to need some minor shimming to properly locate its position relative to the axle. Then again, it might not, since the PMT arms are probably a little wider than stock ones. We'll soon find out.

The PMT Fab arms will need to be drilled out for the sway bar. My idea would be to weld the sleeves to the shim, then insert into the drilled holes on the arm. Not sure if you're need to tack the outer end of the sleeves to the arm or not. If it's a snug fit, I see no reason to do that since the fasteners will hold everything together.

[b-man]

Mick,

What is the width of that sway bar at its widest point, and the center to center distance between the mounting holes?

Reason being I have a bar here that I’m trying to identify, I pulled it from a ‘70 GP but it had a couple of custom brackets adapting it so it clearly wasn’t made for that chassis (A or G body).

Thanks, Bart

[lust4speed]

I'll try and get down to the barn when it cools down this evening and get some measurements.

[b-man]

Thanks Mick.

The one I have is 1” in diameter, 40-3/8” at the widest point near the rearmost mounting holes and 5-1/2” center to center at the mounting holes (slotted).

[lust4speed]

Got the measurements:

44.5" at the centerline of the rear bolt holes where they contact the sway bar spacers. To fit properly the bar should have been 45.5" to omit spacers (additional 1/2" per side).

Bolt centerlines on both sides were 5-7/8". I really tried to stretch the tape to get an even six inches but no dice. The swaybar holes were simple 1/2" holes with no slotting so I just C-clamped the bar in place and drilled through the control arms.

[b-man]

Thank you Mick for heading into the oven, er barn and taking those measurements.

[MPKind]

How much wider is the bushing than the arm where the bar is attached?

[lust4speed]

Usually I just cut a 1" piece of 1/2" black pipe and set inside the control arm. I was a little worried about the wagon's weight so I set some 1x2 inch bar stock inside the arm and it slid in snug but I didn't have to force it. So the arm width on the inside is 1" and adding the thickness of the arm metal which is less than 1/16" each side gives about 1.120" total thickness for the arm. The bar stock spacer was .5x1.5 inch by about 8" long.

Addco supplied 7/16" bolts to go in the 1/2" holes and then supplied 1" long 3/8" spacers to go inside the arm. I shelved the incorrect parts and just went with some grade 8 1/2" bolts from Tractor Supply along with Nylock nuts. I put in a curtesy call to Addco and let them know of the improper parts, and the tech said they were out of 7/16" spacers and I told them not to worry about it. One year later I got a shipping envelope from Addco with 7/16" diameter spacers. Guess we have to give them credit for effort.

[MPKind]

Arm width is 1.12”, but what’s the width of the control arm bushing. I ask because the aftermarket arm appears to be the same width as the arm bushing. It could make up for the 1/2” shim you are using. The Ames catalog does sell premade shims for the sway bars they sell. Not sure who heir supplier is, but I’m guessing it’s Addco.

[MPKind]

PMT Fabrication DOES make the rear sway bar for the 65-8 B-Body. I emailed them last weekend, later talked to the owner on the phone. Very knowledgable. The bar isn't shown on the website, but they do make them. Recent addition to the catalog. So if you buy the trailing arm kit with the sway bar, there is a discount vs. buying them separately. They also make the frame braces that attach between the upper and lower forward control arm connections.

I'll be ordering the kit tomorrow and it should arrive in a couple weeks. It's one of those places where they make things per order.

[lust4speed]

Their website was a good read. Wish I had seen it before investing in rebuilding the stock front suspension of the wagon. Post photos when you get the kit in.

[kpbrown31]

It's nice to see PMT does make aftermarket suspension parts for these big cars. Has anyone used their front coil overs? Would they be a little overkill if just being put on a street cruising wagon and not being raced. Car will eventually have a street built 461 or 455. Getting ready to rebuild all my suspension and trying to decide if it's overkill to spend the money vs sticking with a stock set of springs from Coil Spring Specialties. Weighing where I want to spend my money I guess. Perhaps adding some structure to the rear end would be money better spent.

[MPKind]

Another forum member installed the front kit with coil overs on a wagon I think. It’s $3000 all day. Whether your racing or touring, the improvements are substantial. I’m getting the whole package. Front and rear. I had a scare with lower OE ball joints with only 1500 miles nearly coming apart. I’m done with that stuff. I like driving my car. I want it to ride nice, handle well, and keep the tires stuck to the road. I have none of that now. Rear set arrives next week. Install the following. Front set takes awhile to get. 4-6 weeks I guess. Lame. They are made when ordered. Still have manual drum brakes and a single pot master. All new stuff but the master is an easy swap. So I’ll do that this summer yet. Getting kinda like a pro touring.


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