So what will probably break when HP rises?

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airwoofer

airwoofer

Drivetrain limit explorer
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68 fish, currently 340 (maybe 350 HP but who knows?), 904, 8 3/4 3.91 SG. Indestructable with 245 M&H slicks and 255/60 street tires. Going to put a set of M&H 275/60 drag radials. I am also going to slip in a 500 hp / 500 ft-lb SB and run it down the track as well as local street.

What should I expect to be the weak point(s)? What should I be beefing up next?
 
possibly the 7260 u-joints (if thats what u have)...was your tranny rebuilt recently, performance mods done to it? do u have subframe connectors? adequate braking and handling capabilities? is your cooling system up to snuff to cool that beast? big cubes and lots of power makes lots of heat...
 
I would say the u-joint too. Get a new bigger prop.shaft with bigger u joints and you should be fine.
 
I,be ran 120 passes with 7260/7290 u-joints behind my 410.you should look into building your trans. up and get a good stall convertor.jmo
 
The most likely failure will be along the drive shaft/u-joint. It that breaks, other more expensive things are sure to follow.

This is my standard public service announcement for having strong u-joints. Fresh heavy duty J-joint = $20 - $30. U-joint failure = $500 - $1000 or more depending how many other things break along the way.
 

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I got the same 7260 u-joints in a 69 barracuda since 1993...with hundreds of passes using a transbrake...

I think your u-joints will be fine..

In fact I got 3 cars using the small u-joints cause the small 904 yoke....and using drag slicks...
 
684mulas said:
The most likely failure will be along the drive shaft/u-joint. It that breaks, other more expensive things are sure to follow.

This is my standard public service announcement for having strong u-joints. Fresh heavy duty J-joint = $20 - $30. U-joint failure = $500 - $1000 or more depending how many other things break along the way.
Click to expand...
Ouch, thanks for the psa......
 
I remember the guy who used to own this car (we were beeer drinking and pool playing buddies and he didn't much tell me about the hotrod) say when I asked why he wasn't running it much that ...something about the u-joints. I was thinking the driveshaft should get looked at and not sure which this car has.

Thanks everyone. Besides, breaking at the track not only causes delays but can put down oils which piisses off everybody. Just last weekend we had a chebby rear axle come out - luckily he wasn't going very fast when it occurred. Also had a guy get squirrely at the finish line and from what we think he grabbed the wheel with both hands and hit the trans brake button. Car went sideways and hit the wall causing an hour delay. Don't want to be one of those guys.
 
The roll bar install and belts should be first. Trans would be second. It needs the 727-style high gear clutch drum and billet servos. Next, the rear suspension should be in good shape, pinion angle properly set, and a good set of adjustable shocks. That will go a long way to keeping the driveshaft and joints in good shape.
 
Sounds to me like the first thing to break will be your wallet.:thumbrig:
 
So a set of new 7260 universals on the drive shaft... The traction is already an issue with the little 340. Have a set of M&H 275/60 drag radials coming which are that will fit in the stock wheel well / spring location - if they fit at all.

Missed a built 727 with the stroker as it had been stolen by a tranny shop that Mackin had left it at for a refresh. rats. Left the 4sp and all the parts to mount the pdeals with Mackin as I am staying with the auto and maybe whomever buys his car may want to make it a 4sp.
 
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