Q: Possi. Traction Rear End 1967
I have a question that no one out here seems to be able to answer! Did the 1967 Firebird come stock with a 323 possi. traction rear end with traction bar brackets and tortion bar eyes on the top of the punkin? If so were these able to fit a 68? The reason is from backing plate to backing plate is the same length as on my 68? Why are there eyes on the punkin? Thanks for any information you can give me?
A: I think I can answer questions on rear ends. All 67s had the eyelets on top of pumpkin because they used the A body rear (Tempest,GTO) 1967. Cars that had traction bars were any that had a Heavy duty rear end whether it was 326 HO or 400. I have had several 1967 Sprints with traction bar rears. As a matter of fact ALL Sprint Firebirds for 1967 came with factory traction bars. These could be adapted to the 1968 but then I pose the question WHY… with staggered shocks and multileaf springs the 1968 was a better setup. just try going over a washboard road and youll experience this. All posis were an extra cost item, until the Trans AM. Some models it was required tho. On the trim #s I think John boo booed and that was 250 and 270 dk. blue standard buckets and dk.blue bench.
A: There has been a ton of speculation on this issue, but no one has ever come down with an authoriatative answer. However, it has been my experience that as a rule, Firebirds with open rear-ends got one traction bar on the right, while cars with limited-slip rear ends got traction bars on both the right and left.
IF there were, (and that is a big IF), cars which had none, I’d bet it had to do with the ring and pinion ratio. The rear end codes on the third members were independent of the engine/trans installed in the car.It is my guess the traction bars were an after thought to make up for excessive wheel hop due to the mono-leaf springs.
A: I have a 1967 that came with sprint 6 and it has both traction bars…hope this helps …
A: In the past, there have been a couple of threads concerning the factory traction bars on 1967 Firebirds, in particuliar, the rules governing the hows & whys of whether you got none, one or two of them.
While researching differentials and available axle ratios, I came across what I believe is the definitive answer to those discussions. In the Firebird supplement to the 1967 Pontiac Service Manual, it has a section on the rear suspension, propeler shaft and differential. (Section 4 for those who have a copy of this supplement). First, these tranction bars are refered to as Radius Rods in the supplement. Here is the chart, (reproduced here in ascii text), which shows how many radius rods were on the car, based on engine size, transmission type, and in one case, axle ratio:
|RADIUS RODS USED||6-cyl. 1-Bbl.||6-cyl. 4-Bbl.||V-8 2 / 4 Bbl.|
|One on R.H. Side||Man. Trans.||Auto Trans.||Auto Trans.|
|Two||Man. Trans.||Man. Trans.|
*One rod is used if ratio is 3.23:1
I hope this information sheds some informative light on the subject.
Any proposed updates, changes, pictures, and/or corrections, please use our comment section below (may need to click on permalink to access comments feature). Information is subject to change and offered as is without any warranties or guarantees. Please review our Term's Of Use for more information.
Content last modified: January 26, 2014 at 4:30 pm