[DanC]

I'm looking at rebuilding my front end (1978 Firebird) and found no vendors that sell new stamped A arm assemblies. But there are replacement stamped units for every other GM body cars. I can buy the bushings and joints but I would rather just replace the whole assy if possible and preferably TRW.

Then when searching eBay for Firebird parts there are a couple vendors advertising A arms for '80-'96 Caprice, amongst other applications, and the header description says "(also fits 1978 Firebird)"

Does anyone here know of this, or any other, interchange? Or perhaps have a Mitchell Manual and be willing to look it up?

Thanks for any help!

[bhill86]

See if this helps you at all

[DanC]

Originally Posted by bhill86

See if this helps you at all

Hey Brian yes, that helped. Thanks!

From what you shared, I found that no available assembly is compatible. So much for a quick n easy remove/replace on this one!

DanC

[Sirrotica]

According to this article, any 70-81 F body will interchange as long as you have the cross shaft with the assembly. Unless you're going for show points for correctness other parts will interchange.

https://www.lever-family-racing.com/...ypes-of-uppers.

Below they then list other body styles that will also interchange such as A,X, etc.

Year One lists a complete assembly for sale.

https://www.yearone.com/Product/1967-81-camaro/4487nrlh

I hope this is helpful.

[rolling money pits]

I’d love to know the difference between the A arms. Only suspension change, that I’m aware of, was the change in outer wheel bearing size in 77 or 78.

For giggles I looked at UMI and Global West, they both have 1 part covering 70/81 F and 80/96 B body cars. I understand what those arms are intended to do, but they still need to physically fit the different year
chassis.

[Sirrotica]

The cross shaft and bushings changed from what I can tell. The arm is the same geometry, just the holes that the bushings mount in is changed and the cross shaft is slightly different in length.

I had steel bushings made for my 73 T/A back in the late 70s, the OEM bushings were tack welded to the control arm. Near as I can remember the later ones were press fit.

I'm fairly certain the ball joints remain the same also.

The outer wheel bearing and spindle increased in diameter from 78 to 79.

[Skip Fix]

Cross shafts form early to later models. I know my 81 took different upper bushings than my 78.

[DanC]

Originally Posted by Sirrotica

I hope this is helpful.

Thank you for your reply with that interesting and informative article from Lever Family Racing!

And the link to Year One, unfortunately the upper arms are discontinued.

DanC

[DanC]

Originally Posted by rolling money pits

For giggles I looked at UMI and Global West, they both have 1 part covering 70/81 F and 80/96 B body cars. I understand what those arms are intended to do, but they still need to physically fit the different year
chassis.

Thank you for your reply, after reading I checked out UMI and GW too. I saw where UMI covered both those and I agree that they still would need to physically fit if their listing is correct. Interesting though, in the description it states 70-81 F and 80-96 B, but when clicking the "fitment" tab it lists only 70-81 Firebird and Camaro. Then when going to the B body section it does not even show any control arms!

Looking at GW, it has Firebird uppers p/n CTA-71A and Impala as CTA-18A. The lowers were CTA-71L for Firebird and CTA-17L for Standard Impala / CTA-15L Police/Taxi (which is probably a larger ball joint). So unlike UMI, GW is saying they are different, perhaps not interchangeable, somehow!

Perhaps I just need to be "a problem customer" and order a B body upper A arm from a local parts house and physically see if/what the difference is compared to the Firebird.