JP8 -- What's your intention of usage with the car? Those 1.24 TBs are great for improved handling (along with complimenting other items -- shocks, rear suspension/leafs, etc. The 1.24 TBs are the l;argest that ill fit through the common factory stock hex opening of 1.25". I personally suggest those larger bars IF you want to be more serious about handling, especially if you'll be doing it fairly often and for timed competition runs (pylon autocross and/or road course events). Also, consider the pavement you'll be driving on... smooth pavement can be more friendly to larger TBs; rough bumpy roads would not be so friendly... I personally avoid rough roads or simply drive slowly over them.

Stepping up to anything larger in diameter from the factory TBs, even the T/A-AAR/HEMI-Six-Pack bars (relatively weak by today's standards and barely any noticeable change)... will give progressive increased handling... but you still need to improve the shocks, leafs and other components respectively... to some incremental change.

Could you use the 1.24 TBs on a regular street car? Highway is better than street.. YES you could, but consider the tire sidewall's profile, as well as PSI of the tires... all for ride quality.

Don't be afraid of larger TBs.

TBs from 1.12-1.18 (commonly available from Firm Feel) are good compromises for improved handling and ride comfort.... I tried many different setups many years ago... and have stayed with my 1.24 TBs... would never go lower... again... per my driving intentions/setup and usage of the car. BUT, you will likely ... eventually say and realize ... that you could have and should have gone stiffer... say, at least 1.18. you are fortunate to have the 1.24 TBs.. try them and adapt to your driving style/habits.