JamesC

iTrader: (5)

While 82 to 92 a-arms are interchangeable, there are differences.

Bushing sizes are different depending on year*:

Global West offers two Del-A-Lum bushings, one for 82 to mid-83 (p/n 1021), which has a bushing diameter of 1 5/8" and the other for 83-92 (p/n 1022), which has a bushing diameter of 1.915. (The sizes come from Tom Camaro.) http://www.globalwest.net/

*The above mentioned, according to my 82-91 Parts & Illustration Catalog, the 82-84 arms, for example, are no different than the 87-91 with 15" wheels. For all years and applications, 82-91, the bushing part numbers are identical:
14039483 Lower Control Arm Bushing-Front
14039484 Lower Control Arm Bushing-Rear

Steering stops are different depending on wheel size:

Stop, Lwr Cont Arm (82-84) (85-87 Exc 16" Whl) (88-89 Exc Z28) (90-91 Exc 16" Whl).

Stop, Lwr Cont Arm (85-87 W/16" Whl) (88-89 W/Z28) (90-91 W/16" Whl)

Bump stops are different depending on wheel size:

Bumper, Lwr Cont Arm (1982-84) (1985-87 Exc FE2) (1988-91 W/15" Whl) P/N 10068783. Bump stop height for 15" wheels is 2".

*Bumper, Lwr Cont Arm (1985-87 W/FE2) (1988-91 W/16" Whl) P/N 14089443. Bump stop height for 16" wheels is 2 1/4".

*Bump stops for 16" wheels apparently can't be had from auto supply houses, such as Autozone, Napa, and so on (Alternative part numbers for Dorman 31061, for example, show it as a replacement for both 10068783 AND 14089443, though it measures 2"). The bump stops for 16" wheels can be purchased from the following site:

http://www.moderndaymuscle.com/under...x=172&start=40

Note: A common issue with these A-arms is that the end link holes egg out over time. I had mine repaired, but if I were purchasing used, I'd look for something unblemished.

JamesC

lonestar7

iTrader: (1)

Well, the reason I asked is I'm planning to start replacing worn suspension parts on my Formula 350. As best as I can tell, it has the original bushings and ball joints in the control arms. It may still have the original shocks and struts. The have the original GM part numbers stamped on them. And the original owner kept good maintenance records, can't find any receipts for shock replacement.

So I plan to replace all front and rear suspension bushings, ball joints, shocks and struts, springs. I'm also installing a wonder bar and replacing the strut tower chamber plates with ones with better bushings. I've looked at the poly bushings but I'm thinking I'll stick with the stock rubber type for a smoother ride. I've found you can get a complete set of front control arm assemblies complete with bushings, ball joint, and fresh paint for around $200 shipped.
I can find them listed for the 1988 IROC but not for the 1988 Formula, although from what I could tell the appeared to use the same control arm. Looks like this would be the way to go rather than rebuild the old arms if you don't intend to install poly bushings,

TTOP350

iTrader: (8)

How many miles are on it? The idler arm is normally the 1st part that goes to crap..