Six cylinder torsion bars with big block

Fisher said

Ok this thread has me worried now did Mopar make a very sub standard front suspension that made all their cars a danger to drive? If so why were they allowed to be put on the road ! Let's look at this from a numbers poimt and I want real advice not you home grown bull **** opinion! 6 cyl bars are .830 diam / 100lb/inch rate 340 bars are .870 diam/ 120lb/inch rate 383 bars are .890 diam/ 130/inch rate Now my bigblock is 500 lbs 25 more than the advertised weight of the 6 cyl! I am also. Running a glass pun on hood another 30 lb saving! I see no reason to run anything more than the 340 torsion bars on this car!! Any serious input and reasoning would be appreciated! This car will be street driven as if it was 1971!

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The lighter bars have to twist more to support the same amount of weight. In the world of materials science, this greater twist for a given load results in a high level of what is termed 'strain' in the material. Higher strain levels fatigues parts more and distorts them more. So, there is some truth to the lighter bars being more prone to sagging and breaking. BUT, on the other hand a T-bar is a spring like any other spring. (In fact, a coil spring is just a t-bar in a sprial shape....) Strain exists in all springs: broken leafs and coils are not at all unusual.

No, the Mopar suspension is not substandard. In fact F1 cars went to T-bars some years back! Don't sweat that part.

The selection of spring rate in any car depends on weight AND application. The use of the 1.12" diameter T-bar is for a specific handling use. The application depends on what you want. I live in the rural Appalachians, and rally is my motorsport 'fix'. I would not have any use for the 1.12" T-bar on the local roads here (very bumpy in spots, and lots of sudden camber changes that require a lot of suspension travel to maintain traction). Ditto for rally use.

So you need to look at your roads and your intended use to decide. BTW, the standards of 'good' handling have increased somewhat from 1971!