Those gears are your issue. You didnt notice it bc the taller gears you had wasnt spinning the dshaft as fast. Shorten the gear you speed up the rotation of the dshaft which it wasnt designed for so now you have a vibration.


Driveshaft specialties is one of the best. If you are looking to just do a 2 peice then a stock 2 peice will work well too

 

okay i understand now so what what year 2 piece stock driveshaft fits the NNBS?

 

99-02 is what i used, see if you can find out out of a SS or something so you can run a truck 1350 u-joint vs a conversion u-joint. you can always call driveshaft specialties and have them build you a 1 peice if they will even make one that long.

 

Know the best place to look for a drive shaft from an ss ? Is a used one good enough?

 

Its the driveshaft! Replace it or u will see carnage like me! Think my tranny and rear went with the drive shaft!

 

check listings on car-part.com in your area if you want a used one although i'd recommend a custom built driveshaft if you plan on making a habit of going fast if for nothing other than peace of mind. i'd rather spend more to have a quality piece i can depend on rather than take my chances on a used driveshaft and risk getting a bad one, especially in a performance application. a stock truck yeah i'd get a used one.

 

Driveshaft Specialist Inc is the place to go for a 2 peice imho! Costly though...800+ shipping but 800hp an 200+ mph, id rather pay a lil more for the best on the market



"If we build a complete 1350 shaft with 3.5 tubes and 1.5 stub-slip with a GM HD diesel carrier bearing it would run $795 + ship.

Let me know.
Brent"

My email to brent over at driveshaft specialists

 

I had a 70 mph and up vibration and after my rear axle blew up and took out the shaft. I replaced them and my vibration is gone. I suspect these aluminum shafts bend a little bit which causes the vibration moreso than that they lose their balance weights.