[RallyBob]

Keep in mind that this modification will lower the front ride height and alter the roll center. Also, on a GT the spindle will require reaming to fit the larger diameter ball joint, so you'll need to buy or borrow a tapered reamer to do this. If this hasn't scared you away, I can look up the part number for the ball joint I've used in the past.

 

[RallyBob]

The last ones I bought were TRW #10162. don't forget you need to order the ball joint threaded sleeves from a circle-track supply shop too. Assuming you set the bottom of the threaded sleeve in the same position as the flange for the stock press-in type ball joints, the ride height will lower by about 7/8". There is some flexibility here, you can move the position of the new welded sleeve up and down somewhat to alter the ride height to your liking. You will need less negative camber BTW....

Bob

Here's a link to a few photos on an Ascona front a-arm, with the welded-in ball joint sleeve. http://www.opelgt.com/forums/showpost.php?p=40105&postcount=3