Re: With an 18" tire how wide can I go in back on a first gen?
First, please use the old "finger" method to determine how far outta square your car is!
You just walk around it and insert a finger or two, maybe three right at the top center of the wheel well opening and the tire shoulder!
Our cars are known for being off quite a bit STOCK!!
My car fingers about 1 and a 1/2 on the drivers side and almost two on the pass. side!
I have fingered many cars just to see how mine is compared to others and almost all of them seem to be off a schosh regardless too!!
It's a crude method of checking our cars over, but after you do it several times, it turn's out to be a very reliable check methd of the body/chassis placement relationship!
And fwiw, GM thought up to +/- a 1/2" was fine back then so go figure!!!!
PS., and I almost forgot to say to also "finger" the S/F dowel checking holes right at the firewall bends too.... This way you will know if your S/F is right too.