Thought I'd post this here in case there are some racers like myself who are looking to build tubular control arms, using US/domestic parts to retrofit, and I was unable to find this info elsewhere.  Anyway, the OEM tapers of both the ball joints and tie rods are 7 degrees.  The K772 and K6024 varieties WILL fit the 280z steering knuckles.  I have personally confirmed this with the K6024's at least - the K772 p/n is used interchangeably in some cases, and shares the same stud dimensions with a .59" small end & .75" big end.  The K727's will NOT work.  Same taper, but the small end is already too large.  I mention these as they seem to work with some of the later Nissans, and are also used extensively in other strut suspension cars.

 

As for tie rods, the "pinto" variety seems to be the most popular amongst the circle track community.  I've confirmed these studs will also fit the 280Z knuckles, but are a bit on the tight side and a light amount of taper reaming will be in order.

Edited February 28, 201510 yr by preith

Cool. I love background info like that. Even if I'm not going to do anything with it.

 

Did you actually measure the taper, or did you determine the value empirically by verifying that the K6024's fit properly?

My pleasure, and both, measured it first, ordered a stud (going with a monoball solution) and confirmed fitment once it arrived.

Excellent. This kind of info is invaluable when you need it. You don't need it often, but when you do, it's great to have it filed away.

 

Thanks again for sharing!
 

K6024 right here http://www.partsgeek.com/4jqd68w-chevrolet-c10-pickup-ball-joint.html?utm_source=pricegrabber&utm_medium=pf&utm_content=mc&utm_campaign=PartsGeek+Pricegrabber&fp=pp&utm_term=Chevrolet+Ball+Joint

K6024 right here http://www.partsgeek.com/4jqd68w-chevrolet-c10-pickup-ball-joint.html?utm_source=pricegrabber&utm_medium=pf&utm_content=mc&utm_campaign=PartsGeek+Pricegrabber&fp=pp&utm_term=Chevrolet+Ball+Joint

Thanks, but just to clarify, some people might look at that link and wonder WTF we're doing, what I was really after is this, p/n 40-4185-075 in particular:

http://ubmachine.com/balljointspins.html

Which enables the use of a relatively common spherical bearing & housing, like these:

http://ubmachine.com/monoballhousings.html

 

 

May not be worth mentioning, but if there's enough room (depending on the brakes there most likely isn't on the s-30), you can also go with a "screw in" style ball joint with a threaded sleeve:

http://www.speedwaymotors.com/Steel-Upper-Ball-Joint-Sleeve-K772-Style,2126.html

http://www.speedwaymotors.com/Howe-Racing-22320S-1968-89-Chrysler-K772-Style-Upper-Ball-Joint-Steel,7935.html

 

 

Also, to further complicate matters, it appears the K6024 ball joints have changed dimensions over the years, now requiring a taper ream to retrofit on an older truck for which it's originally intended.  So if someone were to pick up an OEM unit off an old Chevy to compare, or perhaps the one linked above, they'd probably be more confused, see notes:

http://www.speedwaymotors.com/Speedway-1963-71-Truck-K6024-Style-Upper-Ball-Joint,2245.html

Edited March 3, 201510 yr by preith