Hey can some1 Measure a upper control arm bolit hole to bolt hole
The dimension I have written down from sometime back in the '90's is 10-3/8"
Chuck you da man
I am assuming you are talking about the rear upper of course.
10.203" to 10.240" with a brand new bushing installed.
If you're making some adjustable ones, somewhere in the vicinity of the two measurements will be fine.
If you're making fixed-length ones, pick a dimension 10.25-10.375". c-to-c
We used the 10-3/8" as a reference back when we made them at KB. I used a set couple sets of fixed length ones I made up for my own cars as well for a few years at 10-3/8", with no issues.
che got back to me this am and said they set them at 10-1/4
I have been modifying those arms for years. And if you go longer than 10.250 you will get a POSITIVE PINION ANGLE. Personally i have never measured one at 10 3/8 but this does not mean some were not that long. Chuck W is well versed on suspension components and i respect his answer. But i personally never measured one at that length. They normally measure around 10.240 or just short of 10 1/4" C-C. If you want a negative pinion angle a shorter upper is how it is accomplished. Like i posted above they normally run 10.203-10.240.
Note you can slot the hole in the arm to set your pinion angle properly. We do this and it has worked out really good. Whenever you lower or raise a car pinion angle should be checked. Most of the times it does not change but if it does the slots come in handy for adjustments. I use 2 washers on either side of the slot and once the pinion angle is set i tack weld them to the arm. Then remove the arm and finish welding them permanently. This is of course after i BOX THEM.