Can 345/18's fit on a mini-tubbed 1967 f-body or is 335/18 the max?? 18 x 12 inch rim. I want the wheel tucked in. How much profile would I go with... 35??

Lastly, what the proper backspacing for a 18x12 rim would I need using both the 335/18 and 345/18 tire??

It depends on how deep the tubs are and how much you notch and box the frame rail.

As for backspacing, buy the tire you want, fabricate a fixture to mount the tire where you want it, and them calculate the BS needed.

Its going to be a 3 inch mini-tub. All metal will be cut up to the frame rail. Shocks will be relocated of course.

I think you will have to actually cut into the frame to make it work, check this link for some good pics:

http://home1.gte.net/rderaad/

http://home1.gte.net/rderaad/68%20camaro%20files/reartubs.htm


and here's a good pic o the frame rail:

http://home1.gte.net/rderaad/68%20camaro%20files/wheelspage%20files/tires4.JPG

Cut into the frame rail to make 345's work or do 335's require cutting the frame rail also??
-Chris

Those are 335's in the picture above. If you look throughout the linked site, you can see the tires are about as far outboard as possible to avoid rub on the fenders. I think even with 315/35/17 you might have to notch the frame a little.

Bret, Thanks for that great info. I thought 335's were the max once the car was mini-tubbed. I had noidea I'd have to cut into the frame rail. Ilooked throughout yu site but could not find any good pics of frame rail & min-tub. Where do i look exactly??

How did you compensate for the cut frame rail to strengthen it?? I'm afraid I'll weaken it and conidering my cars a convertible with 550 HP...its pretty scary!

Lastly, I noticed on your site you used offset uppercontrol arm, shafts...is this mandatory when dropping the car? And lastly how much did you drop the car and which manufacturer's custom springs & shocks are you using??

I apologize if all this info was on already given on your website. -Chris

Sorry I'm just now responding, I was away from the computer this weekend.

The links I provided within the body of the post are to another persons car. "My Site" does not have anything useful for you, I have not even begun to get to that stage of my build.

If you look at the picture I posted above, the frame rail was notched by half of its width in about a 6" or so spot behind the axle.

As for the offset cross shafts, the primary reason I am using them is because they have threaded ends that use castle nut to retain the bushings rather than the small end bolts that are stock. The reason the offset cross shafts are produced is to help in correcting alignment problems. Just dropping the car will not require their use.

I will be running Bilstain shocks and I have a set of off the shelf Moog front coils that will be cut to fit. See this link for more info on the Moogs:

http://www.camaros.net/cgi-bin/forum/ultimatebb.cgi?ubb=get_topic;f=7;t=000929