I just finished upgrading my front suspension with new hotchkis upper control arms, qa1 lower control arms, hotchkis adjustable strut rods and steering rods, qa1 double adjustable shocks, hotchkis 1 1/4" front sway bar and 13/16" rear sway bar and new ball joints. I'm looking for a recommendation on what to do with the torsion bars. It currently has the original small block size bars in it ( 0.88? I believe?). I put a 528 hemi in the car, but the engine is all aluminum so I don't think there is much added weight over an all iron small block. The car will be mainly street driven with maybe a few trips to the drag strip. I don't care about a stiff ride, but I also wasn't sure if there is such thing as too big of a torsion bar that won't work well with the other upgrades that I have, or how much the bigger bars hurt the weight transfer and traction. Any recommendations on brands either? Thanks

The smaller diameter bars will give you a softer ride as long as they can support the weight and are not on the bump stops. I suspect there isn't much weight difference between an all aluminum Hemi and a factory loaded small block.

Back in the early days, Direct Connection suggested that you replace the bigger factory T bars with smaller T bars to aid in front end lift and weight transfer. You already would have those suggested smaller t bars. I suspect your sway bar probably eliminates any advantage those lighter bars would add anyway, the DC also suggested to disconnect both ends of the sway bar for drag racing purposes.

Personally, I would run what you have as a street driven ride, unless this turns into a strict drag racing machine. My comments are all based on old tech from a book, from a guy with a lot of street action, but with no real drag strip experience.

For street driving you should probably put a stiffer bar in there than 0.880. That is a very soft spring by today's standard. It really depends on what front tire you have and how you are going to drive the car. If you want to drive it like a real car then I'd use a bar in the 1 inch range and combine it with a high quality shock such as Koni or Bilstein. If it is just something that cruises over to the burger stand on the weekend then what you have will be fine.

I have an Aluminum Hemi in my Road Runner. It came with a 383 which used the same bars as the TA and AAR cars. It rides nice and does ok, you might want to looking that.

I was thinking ".880 is 383 B/E", but here's a chart.

Front tires are 245/60/15 bf goodrich radial ta's. I'm looking to pretty much build a higher performance street car, not a dedicated race/track car. Just something that performs very well if needed.

Mine has the original heavy duty suspension option bars in it, whatever size that is. I was just guessing that it was in the .880 range

Those tires would work okay with a bar in the 1 inch range. I would highly recommend a good shock though. Koni is the best in my opinion for that type of car although some prefer the Bilsteins.

Everything I build gets big brakes, big bars and Koni shocks. That set of parts works well with modern radial tires and it allows the car to deal with the way people drive now.

At this point, it would probably be good to go and measure what diameter bars you have. We are all guessing what bars your car has, and we could all be wrong.

I'm a drag race guy, not a roundy rounder or sportscar track guy, I left the stock 6 cylinder non air conditioning torsion bars in my old pump gas 1971 Duster, I did use a good set of double adjustable shocks on the front and ended up with double adjustable coil over shocks in the rear, that car worked fine on the street and strip,
Best ET was 9.993 at 134.+ MPH cork up with the air cleaner on using Oregon 92 octane pump swill in the 10.75 to 1 comp. ratio 400 block stroker motor, it road and handled fine on the street also

i have a '65 coronet with a 440 under the hood. the car weighs 3900lbs with me in it and 55% of that is on the front wheels. when i put it together i used .92 bars and had some skinny tires up front. car handled terribly. i added a 1.125" firm feel sway bar and some 15" 70 series radials and the car drove nice and the front end was like it was on rails. i wouldn't go any larger than a .96"; unless you want a log wagon ride.

I used a caliper to measure the torsion bars and they are in the .892-.900 range. I'll try to see if I can find a part number on them to find out for sure which ones they are.

The last three digits of the bar number are usually on the end. Clean it up really good at backside of torsion bar cross member and you may find them.

The list topside posted ins't the old factory numbers for A body 340 bars. Can't vouch for any of the others for B/E cars.

Here's another chart - I didn't check part #s on either chart, but these may be better #s than the 1st one.
All I was thinking was showing the different sizes for different applications.

That's it...

So according to the chart, you have big block bars in your car now. There is only one set with more capacity. Based on that info, I would not swap out your current bars.

According to the tech archives on here, a stock 340 is 525# and a stock Hemi is 765#. While an all aluminum Hemi with some lighter weight internals will drop some significant weight, losing 240# is A LOT of ground to make it equal to a small block. Of course, any weight you can lose is definetly good to have.

In any case, I would be part of the crowd that would say 1" or better bars are the better selection for a street car. Being safe and predicable while on the street is, IMO, provides a better margin of safety to have than obtaining ultimate e.t. at a once or twice a year trip to the bracket drags. You will encounter countless numbers of idiot street drivers that may require evasion driving and this number is considerably higher than the number of passes you will make at the track.

I'll also chime in that with my personal experience in exactly this type of comparison, the thicker bars provide a more consistent e.t. in how they react to changing track conditions compared to the lighter bars and more adjustable suspension set up.




Only in the stock range. There are bars available up to 1.24 from Firm Feel. The Hotchkis system is using something in the 1.1" range as the best compromise of handling and comfort.

PST has 1.03 torsion bars which work really well with a set of Koni adjustable shocks. You'll also need a modern radial tire to make it all work. This combination is the best setup for street driving that I've found. You can get the Koni shocks from Summit racing.

I was able to find the numbers on the bars and they are 778 and 779, so they are the .900 big block bars. I knew they car had the heavy duty suspension option, I'm just surprised that the big block sized ones is what they used. I do agree with your point of view that safer and predictable street driving and handling is more important than a few 100th s of a second for an e.t. once or twice a year if I'm lucky. As someone already stated though, is the difference from a 1.xx bar worth the swap? Do torsion bars lose their strength over time? Thanks for all the help

Torsion bars can loose their strength over time, that is why Chrysler made them adjustable, to make up for lost tension. They are just spring steel. I have seen a few break, but the circumstances surrounding those broken bars is unclear.

The average 426 Hemi was reported to be 150lbs heavier then an average big block (and a big block weighs 100lbs more then the average small block Mopar liked to use average numbers), but I suspect the aluminum heads and intake on your Hemi would pretty much cover that extra 150lbs (and if your "all aluminum" Hemi has an aluminum block, it may be lighter then an average small block). Unless you plan on doing road course racing or parking lot racing where you are really putting extra stress on the torsion bars, I believe your current torsion bars will be just fine. However, if you feel better dropping the money for new bars, go for it. What makes you feel better while your driving your car is all that counts.