I'm looking for direction on aftermarket sway bar kits for my '69.

My car currently has a full factory suspension, all poly bushings, Edelbrock shocks and a Fiberglas rear spring.

406 SBC with a TKO600 and a 3.36 rear.

The factory sway bars, especially the rear, are pretty anemic looking.

Can anyone point me in the right direction of a good kit to replace both the front and rears?

Thanks in advance.

 

Van Steel and or VB&P, both supporting vendors of the Forum, are excellent sources for suspension related components. From components to complete systems they offer a wide variety of hardware and are an excellent resource to talk with for modifying your suspension to suit your driving style.

As an aside, the Big-Block's came with a pretty hearty front sway bar and just upgrading to polyurethane sway bar bushings will increase the effectiveness of your current bars without actually changing the size. Many folks here that road race or autocross these cars will tell you that running no rear bar at all will result in better handling...

Good luck... GUSTO

 

Make sure to upgrade as needed. What I mean by that is the C3 generally has more over steer so don't beef up the rear to much unless the front is over compensated.

That and bigger is also not always better.

 

I have the 1 1/8 front , 9/16 rear sway bars which was the factory heavy duty setup. Bought them used for under a $100. Added all poly bushings and then lowered the car with 550 springs and long bolts.
For a lot less than others kits I have the best handling version of my car that I've had in 16 years.
I'm still going to add Bilsteins, when funds allow.
But my point is you do not need a large rear bar and expensive components to get excellent handling.

 

Unless you like your rear end coming around on you I would go with the stock style rear bars.

GM designed them that way for a reason

 

Some pretty good advice above^

The factory BB bar combination is pretty good as well as the gymkhana sport bars like on my 78 L-82 SBC-1 1/8 inch front bar and 7/16th inch rear bar. My guess without checking is that the 69 front bar even on a BB car is not 1 1/8 inch in diameter-GM did not wake up to using bigger bars until the late 70's in front.

Point 2- C3 corvettes in general do NOT oversteer without big throttle inputs which will make ANY car oversteer. The BB C3's are very nose heavy and will understeer unless throttle induced oversteer is introduced. The SBC C3's are more likely to oversteer at the limit but mainly because the overall chassis weight distribution is MUCH better (rear biased) than the BB cars at roughly F:51%/R:49%. My 78 L-82 gymkhana suspended car has a weight distribution of F:48%:52% rear-great overall balance BUT it will oversteer quicker IF you can push it over its limits.

Point #3: C3's were set up from the factory to push or understeer especially after the Ralph Nader fiasco with the Corvair. My 78 even with the F-41 suspension as delivered from the factory, UNDERSTEERED at the limit.

Point#4:As Qwank has pointed out, do NOT use aftermarket rear sway bars with NON Factory end links since they will restrict trailing arm movement and could induce sudden oversteer. I use the GM 1 1/8 inch factory bar with poly end link and mounting bushing's and a 3/4 inch rear OEM type bar with factory end links and poly mounting bushings. Poly bushings will make a smaller bar much more effective and will mimic the roll resistance of a bigger bar with rubber bushings that will deflect under load.

Chvet73's 1 1/8 inch front bar and GM OEM 9/16 inch rear bar is a great starting point for most applications but depends on the particulars of the car.

Hope that helps!

 

Depends on how you want to use the car. For a street car, use moderate sized bars. Say, 15/16" or one inch or max of 1 1/8" for the front, mounted in rubber. Poly increases the efficiency of the bar, with a corresponding increase in NVH.
You can find a 7/16 or 9/16 rear factory bar. Addco makes a 3/4" rear bar that connects to the factory end links, but you will need to use an 1 1/8 front bar to balance that, probably.
Any thicker than that, and you will have installed a have a solid axle conversion kit. And the C3 frame flexes so much, you will probably be bending the frame as much as you will be loading the tires. Diminishing returns.
The bump steer on our old cars is so bad that guys stiffen up the suspension so much that it hardly moves, in an effort to "bandaid" a fix. Fine on a smooth track, lousy on our pothole covered streets.

 

Having been playing with sway bars for 35 years now on all types of cars
and on my 78 since for 31 years, I can say that sway bars do not effect how hard the suspension feels generally on smooth surfaces nor do poly bushings noticeable effect NVH. Poly control arm bushings have a much greater stiffening effect on the ride of a C3-I have them as well. Sway bars effect how much the body will roll in turns and in combination with a front spreader bar, there is very little frame bending going on, especially in street driving, regardless of the size of the bar. I have poly front end link and mounting bushings on my 1 1/8 inch factory bar and poly on my 3/4 inch OEM type bar and the difference from rubber is negligible in terms of road harshness but BIG difference in roll stiffness.

The OEM rear bars with the OEM end links allow for MUCH trailing arm movement (which is why GM chose that type of end link) and I noticed no difference in ride quality going from the OEM 7/16 inch rear factory bar going to the 3/4 inch OEM type rear bar.

The smallest front bar I would use with a SBC C3 is 1 inch (only if you have to) especially when coupled with the 7/16 rear OEM bar.

Springs and Shocks mostly effective ride stiffness.

 

Very good advise. I learned this the hard way ($) and bought the aftermarket set up for the rear of my '79. First track day I spun the car out twice. Unhooked it and ran the rest of the session just fine. Switched over to the GM unit and BIG difference!

 

I know not whether the rear sway bar on my stock 72 is OEM, but it is the same size as the front one: 3/4. I took the rear on off years ago when doing work back there and never replaced it. From most all the threads I have read, I am just fine without one altogether.

 

My front bar is under an inch and the rear is likely 7/16. I will get under there with a caliper this weekend.

My car is already all poly. Not a piece of rubber to be found.

One small pothole and the car feels like it's gonna vibrate off the road.

Interestingly, my convertible came with no rear bar. I installed a stock one from a 71 Ttop Big Block I bought from someone at work. Before the bar install, I'd lose the rear all the time. It stopped immediately after adding the bar.

So my bars may very well be unbalanced.