Ahh, sounds all too familiar. That's pretty good you got it to 6000. I got mine to 4100 before it let go, so I think you are pretty good there, personally.

https://www.performancetrucks.net/fo...d.php?t=364990

What thunder is saying is typically true on shorter shafts, but for shafts at teh lengths we have 72+, teh steel is actually worse due to the increased weight of the shaft. It lowers the critical speed. I know I've dug it up before but these driveshafts are not torque limited, it's all critical speed for these long one piece aluminums. GM with the 5" 0.082" wall has a design that should get north of 6100 RPM's, but they are obviously balance limited. AL is still your best bet if you want to stay one piece, otherwise you can spin a two piece steel till the cows come home since they are so much shorter and have a higher crit speed due to that shorter length.

 

I decided to go with a one piece aluminum shaft that I am having a race shop build for me. Hopefully this will solve the problem so I can finish the dyno tune and get her back home. Thanks guys for your help

 

[QUOTE=1SlowHoe;3933685]Here is how I fixed mine...3.5" OD Aluminum


[QUOTE]

Thats purdy, who did you have make that for you?

 

Local driveline shop. It was $600