I was wanting to know if the torsion bars on a 5.4 litre truck are the same as a 4.2 litre? Are they stiffer or the same?

 

perty sure they are the same....only time they are different i think is if its a 7700

 

Hope this helps. There are 5 different torsion bars used on the f-150 depending on body style, engine etc.

Diameter 1.24 in, 1.26 in, 1.28 in, 1.30 in and on the 7700 1.36 in.
Lengths 46.87in, 46.95 in , 47.04 in, 47.10 in and on the 770o 52.75 respectively.

they also have different deflection rates and weight per degree ratings as well or spring ratings if you will.