Classic Industries OER front conversion question

TrikyC said
I don't hear about many people replacing the LCA. Is there a reason why this doesnt see as much attention? Whats the reason, in the video, for adding the stiffening metal? I'd assume these can bend/twist under heavy torque situations like road racing or is it just a good idea for improved handling? Just curious about lots of Whys???

The LCA's aren't usually replaced for several reasons. The primary reason is that from '67-76 the LCA's were identical if they didn't have sway bar tabs. So if you do a disk brake upgrade you just buy the disk lower ball joints and you can use them with any of the LCA's. With the UCA's there are two versions, small ball joint (67-72) and large ball joint (73+). So if you upgrade to BBP with the later 73+ disks the spindles take the larger upper ball joint, which doesn't fit into the earlier UCA's. There are adaptors to use the small ball joints with the large ball joint spindles, but most people upgrade to the larger ball joint UCA's. The other thing is the LCA's don't have any built in alignment geometry. With the UCA's the factory design has very little caster built in. Aftermarket tubular UCA's have additional caster built in so you can get more modern alignment numbers. So there are two good reasons to change the UCA's, and no real benefit to changing the LCA.

As for boxing the LCA, there's a couple reasons to do that. One is that they're just stamped steel and they have an open side. So adding the plate to the bottom boxes in the LCA and makes it more resistant to twisting and flexing. The other Jim talks about in the video, the LCA's tend to "open up" at the pivot end. If you clamp the ends of the LCA with the pivot together and then weld the boxing plate on it keeps the ends of the LCA from spreading, further limiting flex in the LCA. I think it's a must do for any car being set up for better handling. Keep in mind these cars were intended to run bias ply tires, which had a lot less grip than even just the plain all season radials (BFG T/A's, Cooper Cobras) that most people run. More grip at the tires means more force on the suspension, which means more flex. The more tire you put under the car up front the more you need to reinforce things to prevent excessive flex.