Does the rear end need to be narrowed after mini-tubbing

[cjnico1]

I have a question. I have a '68 firebird that I will be mini-tubbing. I also need a rear axle for the car, which I will be ordering. My question is should the rear end be narrowed to account for the mini-tubs?? My concern is that if the rear is not narrowed, then I will need a wheel with a significant backspacing....Correct?? If I should order a rear end that is narrower than the stock rear end, how much narrower should it be. Also, what kind of wheel back-spacing should I use. I would like to use the widest tire I can fit in the wheelhouse. For those of you that have been down this road before, can you offer some insight??? Thanks.

[ProdigyCustoms]

The very best thing to do is order your tires and wheels. Mock them up in the wheel wells where they will need to be, and measure inside to inside on the mounting flanges. Then no mistakes.
Now with all that said, a 12" wheel with a 6" backspace with a 335/30 will use a rear around 56" give or take a bit.
But if you do it like i susgested, you will not be sorry.

[cjnico1]

I currently don't have a rear axle for the car. Could someone tell me what the width of the stock axle is for a '68 firebird??? Thanks

[baz67]

Frank a 335 is a little tight in a 68. A 315 may be a better fit. Franks idea on getting the wheels and tires first is the better way. That way you can get an ideal backspace and then measure for rearend width.
Brian

[jannes_z-28]

You can use the stock width on a first gen car together with minitubbing. But then your wheels will not be very deep.

The best thing is to find your wheels first as previously said. Then you can decide on backspacing and look. Then you can order a custommade axle with the correct width.


Jan