75 high boy
 

Need help finding driveline that won't break for a 75 high boy,429,automatic.I have not been able to dyno but am guessing 700hp or more.I have had 7 driveline's built that have twisted in the middle.The company I use will no longer cover under warranty and was unable to build one that would handle it.if I drive it easy it's OK but if I get on it even a little it snaps.At 75 mph I floored it and done the same.I am sure there is a company that handles these things but it's expensive to find out just because it needs to be special made

Built a stock shaft each time? Or heavy wall tubing as part of the build?

I realize this sounds absurd, but what about 4" steam pipe ? Now all you need to find are U-Joints that will hold up.

Driveline
 

the first 2 was stock because I didn't know at the time how the pickup would turn out.the other 5 was heavy wall but they twisted in the middle pretty much instantly. The company I used build drivelines for semis and heavy equipment so that's why I am at a loss.I am not sure if the drive lines they use for racing are any different or not.

Steam pipe
 

I honestly don't know if steam pipe would work or not that's a good question.these drivelines are not small but they twist instantly.I farm so any of the farmer fixes I know of won't work.

I believe the driveshaft is supposed to be the weak link to prevent damage to more expensive components. Just out of curiosity, will it allow you to get rolling if little power is applied? I have had Macks wring driveshafts like pretzels with 3" tubing But heavy duty 4" did the job.

Of course they didn't come close to 700HP !

I have been able to drive it but I am real easy on it.it does have 4 inch.someone mentioned the angle of it so I was going to see if I can find anything about that.I have called so many places but there computers don't show a high boy with 429 auto.originally in had a 390 with Manuel so that's the answers they keep giving me.thanks for response