CPP Tubular arms

[ChevyJr]

So.... I just installed a pair of CPP tubular arms for 60-72 Chevy truck and CANNOT install the pre-installed ball joints that came with it. I have stripped multiple castle nuts and had to rethread the ball joints because the CCP drop spindle wont seat far enough. I've even heated the spindle. My old ball joints have the eye of the ball joint about 2 threads down, the new ones have the eye about 5 threads down. Anyone have an experience like this with these CPP tubular arms? Thanks.