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Got some slicks..... axles ?

Canadian1968

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So I finally got the chance to pick up a set of slicks for my 68. I want to see what the car has and I knew i was reaching the limit of the street tires. I am only hitting 13.2 currently with 105 mph trap. Not very fast at all I know, but I am new to the slick thing. These are obviously going to hook better than the street , hoping to be able to leave full throttle launch?

My question is do I need to worry about axles at all ? The car is basically stock weight . Factory 8 3/4 with 3.23 gears.
 
Ive been very low elevens at 122, on stock 8 3/4 axles, and 10 1/2 x 28 slicks, so, no, i wouldn't worry yet.
 
I ran stock 8 3/4 axles for years in my 11.0 3800lb street car. No issues.
Doug
 
Just my opinion, worry about axles when you get to the 10's. You will have a good bit more to worry about before you get there. Manual transmissions it will clutches, pressure plates, u joints, scatter shields, etc. Automatics will have the same driveline issues and beefing the transmission to hold the HP needed to get there. For just a little better times with what you now have, I don't think you have anything to worry about. Have fun, just keep a watchful eye on things.
 
Great , thanks for the replies guys. The transmission was rebuilt with fresh parts and a shift kit.

Really looking forward to this spring!
 
You will need a Driveline loop. What height are these New slicks? Hopefully 26” because 323 isn’t much gear for 28” tall.

Yes you will be able to leave at wide open throttle.
 
You will need a Driveline loop. What height are these New slicks? Hopefully 26” because 323 isn’t much gear for 28” tall.

Yes you will be able to leave at wide open throttle.

Yes they are 26. That's why it took me a while to find a set someone was getting rid of. The guy is actually bumping up to 4. 10s and 28" tire himself .

Yes the driveloop is on the list. I do belive that's required with any RWD running at the track ? Not only just being a good saftey step in general
 
The 8 3/4" axles will hold up well for quite a while. You may want to check them occasionally. My '65 Coronet was a 426 Street Wedge, 4 speed, with broken gears. It was a 12.70 car. After rebuilding the 8 3/4 I noticed that the pass side axle had an obvious twist in the splines. I got another axle from the junkyard. I also switched to a 727 right away. The 8 3/4 held up fine for a long time.
 
I was going to mention to occassionaly check for spline twist. I had a 73 Cuda that ran high 12's and that was an issue after a lot of passes.
 
https://www.icloud.com/photos/#0fWkwi-X2sFDSXWmuGQG5GRiA

Not sure if this link will work. You may want to fast forward to the end. This was our '69 road runner, running an 8 3/4 rear with 4.30 gears. It had aftermarket Yukon Axles up to this point. Dana with 4.10's now. Car was running 11.20's. That was a fourth round loss, but my son who was driving treed the Pinto. Likely would have sent him to the finals.
 
https://www.icloud.com/photos/#0fWkwi-X2sFDSXWmuGQG5GRiA

Not sure if this link will work. You may want to fast forward to the end. This was our '69 road runner, running an 8 3/4 rear with 4.30 gears. It had aftermarket Yukon Axles up to this point. Dana with 4.10's now. Car was running 11.20's. That was a fourth round loss, but my son who was driving treed the Pinto. Likely would have sent him to the finals.

what broke?
 
what broke?
The passenger side axle broke in half, just after the splines. For some reason, I'm no longer able to post pictures. They were Yukon Axles. The one that did not break was twisted severely.
 
32-spline? Radials or bias? What type of differential? Had the car ever subjected the axles to severe wheel hop?

Just trying to take inventory on what breaks parts. I’m certainly not trying to suggest that an 8-3/4 is as strong as a Dana, but a 32-spline Yukon axle is what it is no matter what housing it lives in. While housing flex could be a contributing issue, I’d argue that a Dana outfitted with the same axles could have had the same results.
 
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30 Spline, factory replacements. Clutch type posi with 4.30 gears and a 9 1/2" converter. No wheel hop ever! Hooks and goes. Running M & H Bias Ply, sticky street tires. Also ran 29.5 x 9 x 15 MT slicks at times. Car 60 foots in the mid 1.50's.
 
3600lb 340 E body pictured, stock 8.3/4" posi, 4.30's 4200 stall, stock 340 springs, snubber good year 10x28's, +250hp N20 of the hit, 535hp no probs, prob over 450ftlbs.
 
8.75 rear 4.56 gears 10.60s at 3300 lbs. 1.43 to 1.45 60 ft 400 cu in motor ladder bars. 29.5 × 10.5 slicks . Twisted stock axles at the splines both sides after several year of racing and street driving. Also broke 2 ring gears and 1 bearing cap. Hope this helps

Photo0086001(1).jpeg
 
by the sounds of it I have nothing to worry about. I'm hoping to get a 12.8 et.

Maybe a 1.7 60ft ? Should be fun..... come on warm weather. Probably 3 months AT least !
 
My question is the car a stick or auto ? I ask because I raced a 340 Dart years ago with the 4-speed and the best it ran was 11.90's as it was usually a low 12 car. Had an 8-3/4 with 4.56 gears and bracket raced it. And I broke a few driveshafts and tranny's and twisted the crap out of my stock axles. But when I race a stick car I launch with the gas pedal on the floor as the clutch comes out and its hard on the drivetrain. Now fast forward 30 plus years and I have my 63 Sport Fury which is a street car that I race sometimes. It has an 8-3/4 with a Detroit Locker and stock axles and has run a best of 10.76 @ 125. It weighs 3700 lbs before I get in the car. I race it once or twice a year at most since 2011 when I put the 493 in it. And its an auto 727 with 4.30's and a 30" tire and has not broke any drivetrain parts or axles yet. And of course the auto has the drivetrain loaded when I nail it so its much easier on the drivetrain. I say if you have an auto you have no worries. If its a stick it can depend on how you launch the car but you should be fine where your at right now. Good luck , Ron
 
When the time comes. Step up to 35 spline axles and matching Sure-Grip/Locker/Spool of your choice.
 
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