For the NP231, it's $575 for the Super Duty SYE and custom X-spline driveshaft (either booted, XB, or with a grease fitting, XC):
Above is the XB (booted). You can save $50 ($525 total) and go with an Advanced Adapters SYE, which is basically the same but comes with a yoke instead of a flange. The advantages of the Super Duty kit are as follow:
- Killer warranty. If you break it, they'll replace it and give you $100.
- Flanged output allows you to use different U-joints in the future if your build plans change.
In either case, you'll get free UPS ground shipping. More details at Tom Woods' site:
http://www.4xshaft.com
Details about the Super Duty SYE warranty and whatnot here:
http://www.4xshaft.com/SD231.html
Pricing details for all options here:
http://www.4xshaft.com/SYE_overview.html
I'm quite happy. Tom Woods has a hell of a reputation in the industry.
Now, as a cheaper alternative you can go with a hack-n-tap SYE and junkyard front XJ driveshaft (as it's double-cardan), but my concerns about this route are twofold:
- Hack-n-tap SYEs aren't reputed as being all that strong, however, failures are relatively few and far between. If you have a steady hand and good tools, you can probably make it pretty solid. Otherwise, you can grab a relatively cheap HD SYE option (such as Advanced Adapters or JB Conversions).
- The stock front XJ driveshaft does suit the needs in this case, but I have reservations about running a shaft that was designed to handle 50% of the engine's output only part of the time as a rear shaft (as then it deals with 100% of the engine's output in 2WD mode, and is technically under load 100% of the time).
Your call, though - whatever budget allows. Many people here run hack-n-tap SYEs with front driveshafts without incident, but it's just a matter of what you're comfortable with.