Im in the midst of a sbc swap on an 87 xj6 and am inquiring as to how people usually connect the driveshaft. I have the standard sedan with the one piece shaft, 700r4 is my transmission for the swap. do i need to have a shop make a new driveshaft or is there a way i can reuse the oem driveshaft? Any info is appreciated, thanks!

 

yes, good idea to have a driveshaft shop make you a shaft but you can DIY if you know what to do.

The best idea is to have a shop make you a new two piece drive shaft, they will only need to shorten the front 1/2 and add a 700R4 yoke.
Two pieces are great for smoothness and strength.

If you are keeping the 2.88 gears a 1 piece drive shaft is OK becasue the tall gearing will keep rotoational speed low enough so vibrations likely wont be an issue. The length...I recall was 52 to 54 inches depending on where you're putting the motor. Generaly speeking 48 inches is the limit for a 1 piece so if you're planning taller gearing like 3:31 or 3.54 gears then I'd strongly suggest a 2 piece.


Fast shafts has premade driveshafts that can be spec'd by the inch, they also make custom drive shafts. You send them your old shaft and tell them the changes you want. I've used them many times. You can expect to pay about 300 for a 1 piece all in and a bit over 500 for a 2 piece with a new center bearing.

 

I like to use Fleet Pride for all my driveshaft work as they are able to shorten, balance, and install any yoke/u-joint you like, and have many locations around the country.