Help! 1987 upper control arms

[Tom A SR]

I am installing new upper control arm bushings on my 1987 C-4. There are a thick and a thin spacer between the frame and the
control arm. My question is, the factory Corvette service manual calls for the thick spacer to be placed on the rear bolt. My car
had the thick spacer on the front bolt. The control arm appears to have never been removed . What is the correct placement for
the thick spacer.
Thanks for any help :eyerole

 

[Hot Rod Roy]

These spacers might need to be exchanged to get the caster and camber adjusted correctly. I'd suggest putting them in the same place you found them. Let the alignment shop tell you if they want them reversed. You will be having the alignment done by a good shop when you finish, right?

The thick spacer on the rear bolts may be a carryover from the earlier c4's, since the alignment specs were for only 3* caster on earlier cars. For improved handling, later cars were upgraded to 6* caster. You want the 6* caster. My '84 is set up with the 6* caster, and the thick spacers are on the front bolts. In case you haven't noticed, FSM's aren't infallible!

 

[Hib Halverson]

That thick spacer moving from the rear upper control arm bolt to the front bolt would mean a huge swing in caster.

The factory location is at the rear. If the one on your car is on the front, then either 1) the car was assembled wrong, 2) (more likely) the last person to had the front upper arms off assembled them incorrectly or 3) the car has had significant collision damage and the spacer locations were changed to solve an alignment problem.

I'd start with the spacers in the rear location, as suggested by the Service Manual. Take the car to an alignment shop and see if it aligns. If it does, problem solved. If it won't, then you may have found why the spacers were moved.

 

[Tom A SR]

Thanks for the replies. I consulted the parts book and a local Corvette shop in my area.
The thick spacer does belong on the front inner for the 84 to 87 years .
Once again thanks for given replies.