Waverly1984

I have restored 5 Cutlass's over several years. Once complete, I give them to a family member. Time for me to restore a "keeper". Have been told "it cannot be done" by well meaning people multiple times over the years, I do not subscribe to such. There are several "it cannot be done" things which I am going to add to my keeper. I have no desire to purchase a new fabricated IRS from the usual suspects (Heidts, Morrison, etc.), so I am researching to determine the best donor car to swap the IRS for my 1972 Cutlass. Ideas are appreciated. Thank you.

alain

Try a 2008 or 2009 Pontiac G8 GT rear
Alain

oldcutlass

A friend and I converted a C2 Vette frame with C4 front and rear suspensions. If you are a good fabricator it can be done. I would suggest a whole new frame setup if that's the route your going. The big brakes will limit you to larger wheel diameters.

joe_padavano

Can it be done? Of course it can. People have been doing Jag rear end swaps for decades.

Unless you have a frame jig and understand suspension geometry, I would stick to an IRS that uses a bolt-in subframe with all the pickup points built in. The T-bird is one such rear. I have no experience with the G8. Of course the added volume occupied by the IRS means that you need a custom gas tank and exhaust routing. The bigger problem is that after doing all that work, the crappy FRONT suspension geometry will still be the limiting factor. If your goal is handling, put your time and money into fixing THAT first. You'll be amazed at how well the car will handle with a proper front suspension geometry and correctly-chosen sway bars and springs. If you want the IRS just to impress the uninformed at cruise night, then do whatever you want.

jaunty75

Wow. You are a nice guy. How do I become part of your family? Any unmarried sisters laying around?

Jeff Stout

Go old school and Corvette IRS. I wouldn't be surprised if lower arms and upper crossmember bolt or weld in just the right spots

joe_padavano

Hint: they don't.

David Sloop

Coworker used a C6 corvette rear in his 69 Camaro.

joe_padavano

You can buy a bolt-in kit for a first gen F-body. A-body, not so much.

7314haywood

May not be direct but it sure looks good.

joe_padavano

The easiest and best way to do that is to just use that part of a Vette frame to clip the back of an A-body frame.

oldcutlass

It's actually not a clip but more of a splice going that route.

Waverly1984

Thank you for the advice. There are many talented car fabricators in my area as one would expect in North Carolina, also have a donor car with a frame in great shape, plan is to make the upgrades on the donor then swap. Fortunate to have a close friend and “retired” fabricator with decades of experience, he has frequently expressed interest in” helping” me with this particular project. He knew this would be out of my depth, now I know too. Your post is spot-on.

Waverly1984

Thank you Joe; When you’re right, you’re right. This is out of my depth, fortunately have a Plan-B and will be taking that path. Your insight and apparent expertise is greatly appreciated. Regarding the information you shared about the front suspension, I have decided that will be addressed at the same time. I have a donor car with a chassis that is good shape, going to do the bulk of work on the donor then do a swap and complete the project. You, along with others kind enough to leave posts, have been very helpful.

Waverly1984

Thank you Alain, excellent idea which I would not have otherwise considered if not for your taking the time to share your knowledge.

Waverly1984

I love my sisters, but I am honor-bound to strictly adhere to “Man Code”. Consistent with said code, I will share a brief story to sum the mindset of my sibling. Years ago, I presented a two-year project, frame-off resto ’71 Vette to my older sister, she seemed ecstatic in the moment, drove it for a few times, but soon returned to her preferred method of transportation; “broom riding”. Cannot change a Zebra’s stripes. Still want to meet any of them?

Waverly1984

Thank you for responding. Collectively, all who responded helped me understand this should be handed over to a professional fabricator. For helping me realize this, I thank all for saving me from what certainly would have been an extremely frustrating endeavor, not to mention all the money I would have thrown at the project before eventually turning over to a pro anyway.

alain

No charger we are all here to help with ideas
Alain
Red W-31