big bolt pattern

with a taller stub you alter the roll centre of the car its like using longer balljoiints (ask a 57 chevy dude)
the effect on handling is much like lowering the car without lowering the car.
go too far though and the upper a arm bump stop doens't work anymore the upper A sits higher, and it would then, with wheels off the ground, allow too much suspenion droop... just don't do dukes of hazzard jumps... all will be ok.

Yeah, I understand the theory. But if you look at extended ball joints for racing they come in 1/2”, 1”, even 1.5”. The difference between an A-body and FMJ spindle is less than 3/8”.

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And here’s the real deal, the changes in geometry were all plotted out in that article. There’s no need to speculate about what might or might not happen, you can literally see the tiny difference in geometry that occurs from using the FMJ spindles, and if you want to apply theory then you can argue why that change is actually positive, depending on your set up.

The factory geometry was for bias ply tires, which use totally different alignment specs and benefit from different geometry than radials do. So just saying that maintaining the factory geometry is best is misinformed.