'64 Wildcat gets larger front sway bar...FINALLY

This saga begins in early 2014 when I purchased a performance sway bar through PST to be installed during my front suspension rebuild. The bar PST sold me was actually made by Addco, P/N 2062, 1.25" and is listed in both of their catalogs as fitting both a '64 Riviera and Wildcat. Before ordering I questioned the fit as a Riviera has a 2" narrower track than does a Wildcat. PST assured me it would fit so I ordered the 2062 bar. When I attempted to install it it was 2" too narrow at the bushing mounts and the end links. There was no way to make it work. I contacted PST and they basically pointed the finger at Addco. I contacted Addco and they pointed their finger at PST. I pointed out both of their catalogs are in error and got a "no ours is not" argument. I asked Addco if I could bring the OE bar and their bar to their facility, about an hour away from me, and they said no, that all returns had to go through PST. As I didn't want to pay $40 shipping for someone's mistake, I gladly sold the 2062 bar to another member here for his Riviera. Here's the 2062 bar with the bushing mounted on the opposite side.


Fast forward to summer of 2016. I still wanted a bigger bar and decided to order Addco's P/N 530 1.125" bar which is supposed to fit Buick '61-64 full size applications. I got the bar at a good price as a close out through Summit Racing. The day I started to install it I noticed that it was about 2" too long at the end link connection, but OK at the bushing locations. Here's the difference with the OE bar and Addco bar aligned in the middle:


The bar was so long that it was hitting the steering knuckle on one side and the brake backing plate on the opposite side. It was also about 1.5" deeper front to back, so much so that it touched the brake lines at the wheel cylinders with the bushing mounts at the OE locations. I was highly PO'd to say the least. I dropped the project and punted until this winter when I planned to re-bend the bar to fit my Wildcat. I did just that using the OE bar as a template and bending each side to align perfectly at the end links with the OE bar using my torches and letting the bar air cool slowly. According to Addco's web site they use 4140 pre hardened barstock and cold form so that they don't have to heat treat their bars. Well, I wanted to heat treat my re-bent bar but took it into work first to check the hardness in an unaffected area between the bushings. Surprise! The bar wasn't hardened. I measured Rockwell C 12.7 to 12.9 in several spots that never saw heat from my rework. That is the as-wrought hardness for 4140 steel bar. So, I refinished the bar (paint was flaking in the bag when received) ad installed it by relocating the bushing mounts 1.5" further forward (I had to drill new holes and trim a gusset on the frame for clearance). The fit was pretty damn good:


I reshaped the end link connection to gain more clearance:



Just for grins I checked the hardness of the 7/8" OE bar and it is Rockwell C 41, so it's tensile strength is nearly double the Addco bar. It will be interesting to see if there is any perceptible difference in handling as a bar's resistance to twisting is determined by the diameter, length of bar from pivot to end links (moment), and tensile strength. If there's no real difference, I will likely pull the modified Addco bar and have it heat treated and hardened to Rockwell C 40-42 next winter.

 

Addco has been around for a long time----they should know by now what fits your Buick!

 

You'd think so. After the second bar failing to fit I did a search on Addco fit problems and you wouldn't believe the hits that came up...even for more popular cars like GM A-bodies. I've also since heard that Hellwig will bend custom bars if you have a pattern or measurements. I'd like to add a rear bar next spring and may try Hellwig. If I end up having to heat treat the Addco front bar (not cheap) I'll likely make my own rear bar and have it heat treated at the same time. PST generally has good stuff but I found their customer service lacking. Don't even get me started on Addco :spank:

 

Ride report: I took my car out for the first ride with the new bar. First off is that the front sits about 1.5" higher which is good for me. It now has a better stance with the 2" lift I added to the rear a few years back to clear our steep drive/road intersection. Ride height with the 60 series tires is now about stock.
The car handled sharp curves much better. It remains nearly flat on taking a 30 mph corner at 35-40 mph. It also removes some of the "float" in the ride. I am pleased how the air shocks in the rear and the stiffer bar up front work together to firm up the ride and improve handling.