View Full Version : g-body/s10 ball joints

12-07-2008, 12:48 PM
well, i cant sleep lately. so ive been messing around on the internet. sometimes thats a good thing, sometimes its not. this is one of times where the jury is still out for me.

i found some references to circle track guys doing stock replacement sourced tall ball joints on their cars. with the S10 being the same as the g-body/metric chassis, this directly applies to me. the numbers they listed were a K6117 and a K3136.
i went to the AFCO site, as this was the cheapest manufacturer that listed tall ball joints by application. their cross reference for their tall G-body ball joint was to.... a K3136 (upper). this ball joint turns out to be sourced from an 82 chevy fullsize truck, 1/2 ton, 2wd. the K6117 (lower) is sourced from 71-76 b-body impala.

armed with this information, i went to the parts store to get some ball joints. i got the stock S10 ones, AFTER i confirmed that they used the exact same part number as a G-body or Metric chassis car. i also had them cross refernce the part numbers i found (which are moog by the way) to the autozoned equivalent. upper was a FA903, and the lower is a FA1014.

i brought all these home, broke out my somewhat accurate measuring tools (only go down to 1/32), my spare spindles and lower control arms, and strated playing on the workbench.

heres my measurments for each.

Lower, FA1014
overall height from mountng surface to top of taper: 3 in
Mount diameter: 2 in
Taper 10 degree
Diameter of threads: 3/4

Lower, stock
overall height from mountng surface to top of taper: 2 21/32
Mount diameter: 2 1/4 in
Taper 10 degree
Diameter of threads: 5/8

which, after reaming the slightly larger hole in the spindle should make the non standard ball joint about 1/4 inch taller.

the upper fit the spindle without issue, and install heights were:
stock: 1 3/8
FA903 1 29/32

making the non standard about 1/2 taller. the only issue is that the mounting flange is different. comparing it to the upper control arm on my truck, it appears that with minor wallering of the holes in the mounting point on the control arm, it should drop right in.

so, using the circle track suggested, non standard replacements would yeild me a 1/4 taller lower, and a 1/2 taller upper. 3/4 total taller effective spindle height. the howe ball joints provide a 1 inch taller effective spindle height.

the problems so far, and then the cost.
problem 1. the hole for the lower ball joint stud is too small, requireing a good reaming
problem 2. the mounting hole is too big, reqireing a bushing, or maybe a good bead from the welder.
problem 3. you have to enlarge the holes for the upper ball joint mount.

the cost so far:
20 ea for the ball joints. 80 total.
bushings are avalible from AFCO for about 20 a pair.
my machinist would charge around 50 bucks for the spindle reaming.
may still need shorter control arms. 110 a pair, UB machine (supposedly theyre working with me on making a set for this swap, but its been 3 months, and still nothing. im beginning to get irritated)

my way, with cntrol arms: 260.00
juslt lowers: 110

now that ive done that, ive begun to go a little stupid. i know the howes are 1/2 inch at either end, and they do all these wonderful things, but theyre 80 ea. so far minimum, were looking at 320.00, ball joints only. just lowers, 160. thats only 50 bucks for a lot of aggrevation on the bottoms. but with building the truck for the $2009 challenge, 50 is still 50 left for something else. but then again, all the great things ive heard about the ball joint swaps are also done with a lower ball joint thats another 1/4 taller. so...

anyway, im stumped. help me to make the decision. does the 1/4 make that much difference, or not? am i asking for trouble with doing it the way the circle track guys do, or is it street car safe?

thanks for any help you can throw my way.