Will stock drive shaft hold up to 500hp/500tq?

[67rsconvert]

I was debating whether to upgrade to spicer ujoints and keep stock shaft or get a whole new drive shaft. What do you think? A

[zbugger]

With that kind of power, it's really recommended that you upgrade. Unless you plan on only grandma driving. (Sorry to any grandma's on the board) If you get on it at all, the stock joints will break. I'd say upgrade anytime you get over 400hp, just for safety.

[Brad]

I think I have the anwser to your question right here......This was a stock driveshaft out of an 89 9c1 caprice police car with roughly 375 rwhp going to it.

Note: This happened in 3rd gear between 60 and 70 mph peddling the car to keep it straight, on a 9" street tire.

click on picture to see a clear/clean pic.


I was on a budget to say the least when this happened. What I did to upgreade was searched ebay for a few weeks until I found somthing to cut down. I ended up with a driveshaft out of a late 90's 4x4,3/4 ton,big block suburban. This had 1350's front and rear. I had it cut to size and put in non greasable u-joiunts (for strength and I also change em every 2-3k miles or less). Oh yeah, it is a 4" diameter unit too! Good luck w/ your project.

[HellTriX]

It will hold, but not for long.

I just ran at the drag strip last friday on a stock driveshaft from a donar car. Looks like stock ujoints. Based on the 1/4 miles times and the weight of my car it comes out to about 490 rear wheel hp. I was launching at 2200 rpm hooking real hard.

I plan to upgrade because I doubt it will take much more.

[Brad]

I forgot to mention, that driveshaft lasted through many a nitrous hit as well as teenage misuse and abuse. I think I put 50k miles of beat down on it.

[67rsconvert]

I guess I should get a replacement in the works. I am going to see if my rebuilt 10bolt will hold up for awhile though! Thanks for the advice and graphic picture. That was all I needed to see!

[RobM]

whats involved in cutting a drive shaft? is it expencive? or can you do it your self

[CAMAROBOY69]

Like you can see in the pic above, driveshafts are hallow so basically all you need to do when replacing the tube is to grind down the ends where it is welded. I have done probably 7 myself but I recomend having a professional do it for you if you plan on getting it balanced perfect. Its not that expensive at all. Usually around $100. You could also get an aluminum driveshaft. More people will reply with great driveshaft ideas.

[carreranova]

It will hold, but not for long.

I just ran at the drag strip last friday on a stock driveshaft from a donar car. Looks like stock ujoints. Based on the 1/4 miles times and the weight of my car it comes out to about 490 rear wheel hp. I was launching at 2200 rpm hooking real hard.

I plan to upgrade because I doubt it will take much more.

490 rwhp would be about 620 fwhp, something I don't think you'll see in a mild 390" SBC. We test these engines regularly on our chassis dyno in the 325-350 rwhp range.

[sporter]

I have about 390 rwhp and more importantly, 470 ftlbs of rw torque. My stock driveshaft was fine with my 2004r and TH-400. I broke the 2004r and the 10 bolt but the factory stock "propeller shaft" was fine, even with slicks. I switched to a Denny's Nitrous Ready shaft when I installed the Moser 9" and the TKO. The stock shaft would never have lived with slicks and a manual trans.

[67rsconvert]

can you upgrade the 8.2 10 bolt pinion yoke to a 1350 u joint compatible unit? My 8.2 10 bolt is built up with eaton posi, superior axles etc. so I was planning to run it til it breaks.