new build new problems rear suspension

[81s]

Hello guys I am long time reader short time poster. I just bought a 68 camaro with some frameworkalready done to it. I measured the rear frame rails today and got 35 inches across incliding the rails and 31 inches in between the rails when I measure maybe 6 inches from where the tail lights are supposed to be. What are the recommendations with these narrowed frame rails. I orig planned on LD3 link but I'm sure you know the story. I will try to post some pics up preyyy soon. I want to road race and street drive mostly but will go draggin every now and again. I would like to use a 9 inch and possibly a watts link. Thanks for your input .