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View Full Version : GM '65 A body question!!!



65BuickGS
02-22-2009, 06:07 PM
I have a 65 skylark,,,stock A arm suspension for now,,have lowering springs and a disk brake set up from a later year chevelle!!!
I want to run 245/45/17's on the front,, on an 8" rim,,,I did a bunch of measuring today,,,and figure I'll need 5.625" of backspace,,,,the only issue im worried about,,,is rubbing the upper ball joint,,,has anyone run anything like this,,,or have any suggestions???

b-man
02-22-2009, 06:38 PM
I have a '64 Tempest, as you know it rides on essentially the same chassis as your car.

Mine has 235/45-17s all around on 17X8s.

Backspacing on all 4 wheels is 4.5", when I had the wheels built I was trying to get them to sit as far out as possible to get a wide track. I also built all 4 the same so I could rotate my tires.

Looking back, a little more backspacing would have been better. Something like 4.75" in front and 5" in the back so I could fit 245/45s and 255/45s.

My car was built with the tall B-body spindles, putting the upper ball joint pretty close to the rim.

You should be able to run a 5" backspace up front with the stock A-arms and short spindles.

Put a bare rim on the front of the car, pretty much any size will do. Put some wood under the bare rim that's tall enough to simulate the tire sidewall, then let the car's weight down on it.

Then you can use the bare rim (after measuring the backspace in it) as a reference, you'll easlily be able to see how much backspacing you can get away with.

I'll tell you one thing that I'm pretty certain of, you won't need nor do you want 5.625" of backspace with an 8" wheel.

I have been upgrading my Tempest lately, going to 18X9" wheels all around. I am removing the B-body spindles and have bought some ATS tall spindles to replace them.

Up front I'm using a 5.5" backspace with a 245/40-18, but again that's with a 9" wide wheel.

You won't need to tuck an 8" wide wheel in quite that far, I'd say 5" at the most.

Measure again.

Good luck, Bart

65BuickGS
02-23-2009, 10:57 AM
Thanks for the reply!!!
I will have to measure again,,,I thought the BS I was mentioned was pretty extreme,,,I "thought" most guys with those years of GM A bodies where running somewhere in the 4.5 to 5" range!!!!
When you go to the taller spindle set up,,,does it change the BS needed on wheels,,,make the track wider or narrower??

yellow heap
02-23-2009, 12:22 PM
I run a 64 ss with tall Caddy spindles-I think the Caddy spindles kick out the wheel about 1 inch-I run 16x8 rims with a 5 inch back spacing all around the car.
I don't know if the Ats spindles move the wheels out or not.

gearheads78
02-23-2009, 01:32 PM
I'm running a 18 x 9 with 6.5" bs up front so a 18 x 8 with 5.5 would fit also perfect on my car.

CapSS92
02-23-2009, 01:42 PM
I run an 18x8.5 with 4.5 and McGaughys upper tubular arms,stock spindles,Speedtech C5 disc brake kit with 13" rotors, and airride and it fits fine.