I have a 1989 Trans Am GTA Convertible. Conversion done by ASC. Obviously it squeaks and creeks and I'm looking for advise on improving those issues and the body twist. Here are my questions:
- Is there a difference between a convertible that was available directly from Pontiac as a convertible and one that had to be ordered from Pontiac as a T-Top or hard top model and then get shipped from the dealer to a conversion place as far as the suspension goes?

- I am more of an engine guy but I have tried to read up on all those nice items for sale in the suspension department. Tubular A arms, K member, STB, wonderbar, panhard bars, subframe connectors.... Not only am I thoroughly confused, total long up the cost of all of them is staggering. So what I would like to know is what would yield the most improvement to the body flex / creek / squeak issues? Subframe connectors? STB?

I tried to search both the convertible forum and the suspension forum so please don't shoot me if I overlooked the answer.

 

subframe connectors would do the most, short of installing a cage in the car.

you will need connectors made for the verts, since they have their own unique bracing installed down the rockers. The subframe connectors from Alston ( Top Down Solutions, TDS sells these) and MAC, are 2 that will work with the verts since they use the inner rear frame section and the trans subframe for the connection points.

All the other parts you listed will not all to chassis rigidity. The STB helps keep the front end from flexing in a hard turn, but you really need to replace the factory front strut mounts with aftermarket ones with bearing before you will see any great benefit from that piece.

 

Thanks for the information. That will help me get started.

 

There's no such thing as a convertible available directly from Pontiac (or Chevy for that matter). They were all converted from coupes aftermarket. FYI