74 c10 5/7 Drop-Will It Rub??

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projectmidnight74

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Evening gents.
Rebuilding my dads old 74 c 10. I went really aggressive before I began researching forums. So I have a 5/7 drop installed. Looks amazing, but I'm now curious as we get close to finishing, will the 20's rub the new inner fenders. Anyone ever went this deep with a drop. Im just trying to get ahead of any issues. If I gotta get new tubs, I would rather do it now, than right at the finish line. Let me know what you guys think.
And also, SBC 350/3 inch exhaust with widomaker 10's. ITS A ROWDY MF LOL!
 

Turbo4whl

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Not knowing what the tire diameter you have, most likely they will rub. There are 2 things you can do before you go to the trouble of front tub inner fenders. Reverse any hardware that bolts items to the inner fenders. Pan head bolts facing up, nuts on the top.

Next, install air bags in the front coil springs. You will only need about 25 PSI in the bag, just enough to raise it up enough. I did not use any line kit, just fill the Schrader valve and put a metal valve cap on. No lines to leak or get torn off.
 

bluex

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We need to know your tire size before we can say if it might rub or not.
 

Elliot W

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I dropped mine close to your specs. Axle flip kit in the back and 2" drop springs, 2.5" drop spindles in the front. Ridler wheels 20x8.5, 4.75BS front, 20x10, 5.5BS in back. Fullway tires 245/45 and 275/45, no rubbing while driving normal, some minor rubbing at full turn.
 

projectmidnight74

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I dropped mine close to your specs. Axle flip kit in the back and 2" drop springs, 2.5" drop spindles in the front. Ridler wheels 20x8.5, 4.75BS front, 20x10, 5.5BS in back. Fullway tires 245/45 and 275/45, no rubbing while driving normal, some minor rubbing at full turn.
That's the same tire combo I'm running
 

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While there is no guarantees as there is a lot of factors such as wheel/ tire size, backspacing, etc; the 73-80 inner fender usually is fine on a 5", the 80+ almost always rub.

 

Ricko1966

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I do not know how to describe this best but I'm going to try. The spindle if looked straight down on it where the ball joints turn there is no front to rear motion just twist. The further you get from that centerline the more the wheels move front to back in the turn. Spacers,wheel width,wheel offset Will change how far the wheel moves forward and back in a turn a extra 1/2 inch one way or the other might be the difference between rubbing and not rubbing
 

Bennyt

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I do not know how to describe this best but I'm going to try. The spindle if looked straight down on it where the ball joints turn there is no front to rear motion just twist. The further you get from that centerline the more the wheels move front to back in the turn. Spacers,wheel width,wheel offset Will change how far the wheel moves forward and back in a turn a extra 1/2 inch one way or the other might be the difference between rubbing and not rubbing
I believe you are referring to track width.

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Ricko1966

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I believe you are referring to track width.

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No, I was saying the further out you move the wheel from the center of the ball joints the wheels don't just turn they sweep forward and backwards when they turn.
 

Ricko1966

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Okay I found an example. Look how far rear wards the tire moves when you turn. The further you get from the ball joints centerline the more front to rear movement your wheel has in a turn. Right in the centerline it's a twist an inch from the centerline its an arc a foot from the centerline its a bigger arc.So your wheel are moving forward and back not just turning.. It's a little more complicated than that. But that's the best I can do.
 

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Bennyt

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Okay I found an example. Look how far rear wards the tire moves when you turn. The further you get from the ball joints centerline the more front to rear movement your wheel has in a turn. Right in the centerline it's a twist an inch from the centerline its an arc a foot from the centerline its a bigger arc.So your wheel are moving forward and back not just turning.. It's a little more complicated than that. But that's the best I can do.
Great example!

Yes an increased track width creating Positive Scrub Radius as a result of changing to negative offset wheels.
 

projectmidnight74

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So, here we are. Fenders on and boy it's kinda tight. Turn radius is ok I think but the vertical clearance is going to be sketchy. I can't fit my hand all the way inside the tub. So I sense some scrub on bounce issues coming.
 

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bluex

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A 255/40 is a bit taller than the 245/40 that most people run on that drop an it occasionally rubs on larger dips. Yours will rub more frequently with the taller tire....
 

projectmidnight74

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A 255/40 is a bit taller than the 245/40 that most people run on that drop an it occasionally rubs on larger dips. Yours will rub more frequently with the taller tire....
So, I need new front tires in other words lol
 

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