A-body vs fmj spindles

Just curious what everyone’s take is on the a-body vs Fmj spindle in a handling application? It seems as though the fmj spindle is not only lighter but has better “numbers” than the a-body counterpart with the exception of have a higher roll center and slightly worse toe change on extreme extension. I’m personally building an a-body and an e-body with handling in mind and have both sets of knuckles to chose from. Which should I use?

Use which ever one you can find. My experience is that whatever alignment differences they may have, it takes a better driver than me to tell the difference.

I would use the FMJ knuckles, especially if you are going to drive it hard. If you are going to drive it hard you'll need big brakes and there is more room on the FMJ knuckle for a big caliper.

The FJM units do have lighter weight and better numbers. Even the higher roll center is an advantage as it reduces the moment arm length to the Center Of Gravity. With that said though, the difference they provide would never be noticed by the butt dyno and driver variables mean it may not even be evident on a stop watch.

However, there are guys out there willing to pay for the A body spindles while others give away the FJM spindles.

this right here. sell off the A-body spindles and use the money toward your brake choice.
the debate on which spindle is best and the supposed pitfalls of the FMJ spindle has been ongoing since i joined here years ago.
i have done dozens of conversions with the FMJ spindles, as well as several with the A-body ones, and i couldn't tell a lick of difference.
no upper balljoint "overextension" either, contrary to the popular magazine article, "disco-tech".

Brakes are Mercedes 13.5” rotors on hubs machined out of old rotors with Gen 3 viper calipers.
Thanks everyone for your comments!

Cool. I'm looking at trying something similar with some 14" rotors I have from a 2000 BMW M5. This would be on a 73 E-body. Would I be better off looking at the FMJ knuckle too?