Wheel Back Spacing Question For A 70 RR With Wilwood Disc Brake Kits....

[soundhd]

Have a 70 RR with power 4 wheel drum brakes. Going to convert to front disc using a Wilwood bolt on kit (will be doing the rears later in the year). Have to move up to a 15" wheel. Have picked a wheel from Centerline. Going to be 15"x7". Have 3 choices for back spacing. 3.5, 4.0 and 4.5 inches. Can anyone tell me if they will all fit and what the pros and cons are for each? Will have a P235/60R15 Goodrich Radial T/A tire mounted on the wheels.

Thanks

 

[benno440]

thats a skinny wheel and tire for that car,i would go the least backspacing 3.5 as it will look more dishy. it will work fine on your application, i have a 10" rim with 5" backspacing and still leaves me about 1.5" to the lip

 

[kdtjb]

I was thinking at least an 8" wheel with 4 1/2" at the most back spacing. 4" would be better if they have it. 70s have lots of room back there.

 

[bigmanjbmopar]

Wondering if 8" wheels with 4.5" backspacing would work up front as well as back? 15x8

 

[benno440]

Wondering if 8" wheels with 4.5" backspacing would work up front as well as back? 15x8

definetly.
i have seen 275 tires on the front of some of these b bodies. i just put 18 x 8 with 245 tire on and heaps of room

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definetly.
i have seen 275 tires on the front of some of these b bodies. i just put 18 x 8 with 245 tire on and heaps of room

closer to 5" BS would be ideal but 4.5 will work

 

[bigmanjbmopar]

I think I am going to go with 245 / 60 x 15 x 8" all around This should keep up with the gears I have and not raise me up anymore than I already am.

Found some MT in that size and can go on up to a 8.5" wheel. Not the full speed rating I wanted but I don't think I am going to maintain over 100 mph for long duration's lol

http://www.summitracing.com/parts/mtt-6027


Here is the gear ratio calculator, If I went up to 255's I would most likely need 3.91 gears wonder if this has to do with some peeps issue with having to work harder to do burn outs? my 245 14 x 7 just light up with a touch of the gas and I want to keep that as much as possible.

http://www.summitracing.com/popup/calcsandtools/gear-ratio-calculator


OOPS! Changed the fronts to 15x7's after reading this don't want to have any issues!
http://www.vintagewheelworks.com/tech-wheel-tire.php#68b