426 Hemi torque boxes or frame extensions

[rick]

Thank u all I will do both 

[HPP]

IMO, torque boxes and subframe connectors are required for ANY horsepower level car that will be driven. Aside from firming up the chassis for the suspension to work, the flex they eliminate means fewer squeaks and rattles; doors, hood, and trunks will all closer better, fender gaps will remain consistent over time; window gaskets will seal better for longer, paint cracks from flex are eliminated.

Really the only reason NOT to have them is for a concourse restoration that will be judged. Everyone else should consider using them.

BTW, XV is back in business. Look for them under XV Engineering or XV Racing Products. Products is important to include in that search or you end up at a Honda tuner site. Unfortunately, they no longer have all their engineering videos.

[MxRacer855]

both in my opinion

I agree. If you're going to do one or the other... install both!

US Car Tool makes great ones for cheap prices.

[troy.70R/T]

Both. Any Charger I ever own will have both.