68 GT convertible project

I emailed R/T Specialties about the lift bracket clip/pin. He said that the one listed for hardtops is the one I need.

I mounted the springs and rear end tonight. I was worried how much clearance I'd have between the axle tube and the shocks.(brake hoses) I thought I'd better measure it to be sure so the rear end went under the car sooner then I planned. Here is a picture with the back of the car supported by the springs. It will sag a little more with the interior all installed but I doubt it will be much. Right now I've got 11" from the axle centerline to the wheel well lip. A 20" wheel should be 21" from lip to lip so, the top of the wheel should just disappear in the wheel well with the full weight on the springs. This is with the front spring bolt in the lower hole. I can still drop it lower if I need to. It all depends on how low I can get the front.
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Here is a picture of the outer wheel well. I've got an arrow pointing towards a lip that sticks out. Is this a convertible thing or do all A-bodies of this vintage have it? This lip is even with the wheel well lip. It might even stick in a little farther. This is going to limit wheel width. I thought I'd be able to trim the lip somewhat for extra clearance but the tire is going to hit the wheel well before I even get out to the lip. I just took some rough/quick measurements but a 20x10 wheel with 5-3/4 backspacing will leave 1/2" gap at the springs and about 3/4" at the wheel lip.
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