Thanks to all in advance for any help. I am noticing an abundance of affordable 3:46 2004 - up GT rear ends around. What are the practicalities/drawbacks to trying to wedge one in a 67 GTO? Are there any kits? how durable are they?

Bilomoto  

Well I honestly feel it would be painfully hard to get one to work in there. I have thought about doing it with my Trans Am, in favor of a road racing setup, but never gave it more thought than a "hey that might be cool" idea flash.

The problem area would be the control arms. You would have to have brackets made to allow this to work, or possibly make your own control arms as well. This would be a very costly area, so that is probably why there aren't but maybe a few independent rear suspension kits available for any vehicle. I would look closer at a later Ford Mustang's rear before I looked at a GTO. The GTO was made and designed around IRS, while the Mustang had IRS added later in the production run. They also feature the ability to switch back to a solid axle setup, if desired.

The GTO's haven't been too successful with the IRS in a serious drag application, but they deliver a ride that can not be achieved by a solid axle. Now if you are just going to cruise or road race, IRS can not be beat, hands down. But if you are looking to drag race the car often, you may want to look elsewhere.  

CamaroSS:
Well I honestly feel it would be painfully hard to get one to work in there. I have thought about doing it with my Trans Am, in favor of a road racing setup, but never gave it more thought than a "hey that might be cool" idea flash.

The problem area would be the control arms. You would have to have brackets made to allow this to work, or possibly make your own control arms as well. This would be a very costly area, so that is probably why there aren't but maybe a few independent rear suspension kits available for any vehicle. I would look closer at a later Ford Mustang's rear before I looked at a GTO. The GTO was made and designed around IRS, while the Mustang had IRS added later in the production run. They also feature the ability to switch back to a solid axle setup, if desired.

The GTO's haven't been too successful with the IRS in a serious drag application, but they deliver a ride that can not be achieved by a solid axle. Now if you are just going to cruise or road race, IRS can not be beat, hands down. But if you are looking to drag race the car often, you may want to look elsewhere.

Well said. That seems logical. Thank you for taking the time to reply.

    Bilomoto